Subtle Sport: The 1963-1971 Mercedes W113 Roadsters

Some cars can be understood only in the context of their time; others were puzzling in their day, but now make perfect sense. When the six-cylinder 230SL debuted 50 years ago this past March, it was a considerable departure from previous Mercedes sports cars and some observers weren’t quite sure what to make of it. However, it established a very successful niche that’s still going strong today. In this installment of Ate Up With Motor, we examine the origins and development of the Mercedes-Benz W113 series: the 1963–1971 Mercedes-Benz 230SL, 250SL, and 280SL.

1970 Mercedes 280SL (W113) badge

THE ENIGMA

In their day, the 1963–1971 Mercedes-Benz 230SL, 250SL, and 280SL (known internally by their chassis code, W113) had a unique capacity to both impress and perplex critics. While the W113s were attractive, superbly built automobiles with many virtues, contemporary reviewers were often driven to distraction trying to figure out how to appropriately assess those virtues and decide to what rivals they should be compared.

Past competition glories aside, the Mercedes-Benz name connoted luxury cars, and the W113 certainly carried a luxury price tag. On the other hand, since it was a close-coupled two-seat roadster whose designation recalled the legendary 300SL, there was a natural impulse to regard the W113 as a high-end sports car like the E-type Jaguar or the Chevrolet Corvette. However, direct comparisons to either other sports cars or other high-end American or European luxury convertibles generally left the Mercedes roadsters seeming a little out of place.

1970 Mercedes 280SL (W113) side
A U.S.-spec 1970 Mercedes-Benz 280SL, sporting the “Pagoda” hardtop that gives the W113 series its nickname. (author photo)

Perhaps the W113’s nearest analogue was the original two-seat Ford Thunderbird: a sporty-looking “personal car” that emphasized dignity and comfort over outright performance. Of course, the Mercedes was a good deal more expensive than the T-Bird had ever been, but the two were certainly similar in concept.

Mercedes-Benz during this era was nothing if not sternly rational, so we must assume that positioning the 230SL, 250SL, and 280SL in this way was deliberate. To understand the reasoning, we must step back a few years to the mid-fifties and the introduction of Mercedes’ four-cylinder 190SL.

THE STILLBORN W127

As we’ve previously discussed, the 190SL (known internally as the W121) was the brainchild of Mercedes-Benz’s U.S. importer through 1958, the inimitable Max Hoffman. Introduced at the 1955 Geneva show, the 190SL was a cheaper companion to the bigger, raced-derived Mercedes 300SL. The 190SL was based on the contemporary Mercedes 180 “Ponton” sedan, but featured new styling by Walter Häcker and a 1,897 cc (116 cu. in.) SOHC four with 105 PS DIN (77 kW; 120 bhp SAE).

The 190SL was cute, but its public acceptance was hampered by a combination of high price and modest performance. The 190SL wasn’t tragically slow by the standards of the time — and straight-line performance was not necessarily the first priority of fifties sports car buyers in any case — but the price tag made it hard to ignore the fact that the little roadster could be handily dispatched by an Austin-Healey 100 or a Triumph TR3, either of which cost substantially less. Even Mercedes engineers acknowledged early on that the 190SL was underpowered.

1961 Mercedes 190SL (W121) front 3q
At launch, the 190SL cost 16,500 DM in West Germany, $3,998 POE in the U.S., over $1,000 more than the much faster Austin-Healey 100. With 120 gross horsepower, the Mercedes was capable of 0-60 mph (0-97 km/h) in the low 13-second range and a top speed of 106-109 mph (170-175 km/h). (author photo)

Extracting more power from the 190SL’s M121 four-cylinder engine was feasible, but for the era, its specific output (63.3 bhp/liter) was already ambitious, and raising it further would have meant significant sacrifices in refinement and tractability. A more promising alternative was to substitute the 2,195 cc (134 cu. in.) six from the 220 (W180 sedan). In stock form, with two Solex carburetors, the small six was actually less powerful than the four, albeit with more torque, but experiments showed that Bosch mechanical fuel injection would provide a healthy increase in power without any loss of smoothness.

In 1956, engineer Erich Waxenberger shoehorned the injected six, dubbed M127, into the modified engine bays of several 190SL test mules. Testing at the Nürburgring revealed that the marriage of engine and platform was still not ideal, but the six was much more pleasant than was the M121 and provided much-improved performance.

1961 Mercedes 190SL (W121) rear 3q
The Mercedes-Benz 190SL rode the same 94.5-inch (2,400mm) wheelbase as the bigger 300SL (and the later W113 roadsters), but at 166.1 inches (4,220 mm) overall, it was 13.8 inches (350 mm) shorter than the 300SL roadster. (author photo)

Technical director Fritz Nallinger recommended the six-cylinder 190SL for production and assigned the car a new W127 chassis code, but the project was shelved in the spring of 1957. The idea of a smaller six-cylinder sports car was promising, but passenger car development chief Rudolf Uhlenhaut was already planning to phase out the aging Ponton in favor of a newer and much more modern platform (known internally by W110/W111/W112 chassis codes). The new cars would have substantial structural differences from the Ponton — they would be true monocoques incorporating front and rear crumple zones, a safety innovation devised by design engineer Béla Barényi — and so it didn’t make sense to launch another derivative of the outgoing car.

Since the basic idea of the W127 had been sound, the board decided to shift the project to an all-new six-cylinder sports car that would be based on the W111 platform. That car, initial planning for which began in October 1958, would be known internally as the W113.

300SL IN TWILIGHT

In the meantime, buyers who wanted a more powerful Mercedes-Benz sports car than the 190SL had another option: the mighty 300SL (W198), the street-going derivative of the Le Mans-winning W194. With its fuel-injected 2,996 cc (183 cu. in.) six, the 300SL had more than twice the power of its 190SL sister, and cost close to twice as much. With the right axle ratio, the 300SL was among the world’s fastest cars, and certainly one of the most attractive.

Handsome as it was, the 300SL was not for everyone. Entry and exit were awkward, ventilation was poor, and the swing-axle rear suspension had unpleasant characteristics at the limit. The roadster, which replaced the coupe in mid-1957, had a better-behaved suspension and conventional doors, but was still complex and finicky for street use.

1960 Mercedes-Benz 300SL (W198) roadster side © 2007 Stahlkocher (CC BY-SA 3.0 Unported)
No less dramatic-looking than its gull-wing predecessor, the W198 300SL roadster was about 2 inches (50 mm) longer than the 300SL coupe, had a reworked tubular chassis permitting the use of conventional doors, and switched from a conventional swing axle to the low-pivot rear suspension from the Ponton sedans. The revised suspension allowed both halfshafts to pivot around a common point, providing a greater effective swing arm length to minimize camber change in turns and a lower roll center to reduce the roll stiffness in back and discourage “jacking” at the limit. (Photo: “Mercedes-Benz 300 SL Roadster r” © 2007 Stahlkocher; resized and used under a Creative Commons Attribution-ShareAlike 3.0 Unported license)

While Mercedes continued to make functional updates to the 300SL almost until the end of production, there wasn’t much incentive to create a direct successor. The 300SL helped to sustain the luster of past racing victories, but Mercedes had withdrawn from Grand Prix competition in 1955 after the accident at Le Mans that killed works driver Pierre Levegh and dozens of spectators. This left the 300SL as a pretty but aging orphan that was undoubtedly expensive to build and sold in tiny numbers: no more than a few hundred cars a year. From a practical standpoint, a milder, less-expensive six-cylinder sports car seemed a much better bet. However, that project would have to wait its turn.

THE HECKFLOSSE SHEDS ITS FINS

At the Frankfurt Auto Show in the fall of 1959, Mercedes launched the first of its new sedans, the six-cylinder (W111) 220b, 220Sb and 220SEb. All had the 2,195 cc (134 cu. in.) six with between 95 and 120 PS (70 to 88 kW), and all sported stubby tailfins that earned the new models their nickname: Heckflosse, or “fintail.” The fins, a nod to contemporary American styling themes, were omitted from the subsequent two-door coupes, the first of which debuted at the 1961 Geneva show.

The W113 sports car was the last major Heckflosse derivative to be developed. The sports car’s basic engineering “package” was not approved until about four months before the W111 sedans went on sale and full-size clay models were not ready until the summer of 1961, three months after the debut of the 220SE coupe. Production approval followed later that year.

Mercedes-Benz 220Sb (W111) sedan front 3q © 2007 Maly LOLek (CC BY-SA 3.0 Unported)
A W111 Heckflosse sedan shows off its namesake tail fins (which Mercedes called Peilstege, “sightlines,” implying that their purpose was to enable to the driver to see the rear fenders when parking). The W111 sedans were 191.9 inches (4,750 mm) long on a 108.3-inch (2,750mm) wheelbase; the long-wheelbase W112 (300SEL) had a 4-inch (100mm) longer wheelbase for greater rear seat room. This is a late-production 220S automatic with the 2,195 cc (134 cu. in.) M180 six, making 110 PS DIN (81 kW; 124 bhp SAE gross) with two Solex carburetors. (Photo: “Mercedes W111 220SB MTP07” © 2007 Maly LOLek; resized and used under a Creative Commons Attribution-ShareAlike 3.0 Unported license)

There’s a certain irony in the fact that many of the people responsible for the design of these resolutely Teutonic automobiles were not actually German. Mercedes-Benz chief stylist Friedrich Geiger was originally from Baden-Württemberg, but chief body engineer Karl Wilfert, who had ultimate responsibility for passenger car design, was Viennese, as was Béla Barényi. Designer Paul Bracq, who is typically credited with the W113’s design (along with that of the W111 coupe), was from Bordeaux, while future Mercedes design chief Bruno Sacco, who had joined the design office in Sindelfingen in early 1958 and was involved in the W113’s development, was Italian. Technical director Fritz Nallinger was from Esslingen, but Rudi Uhlenhaut, chief engineer for passenger car development, had been born in London to an English mother.

Nonetheless, the fruit of their labors could hardly have been more Germanic. Where Jaguar’s new E-type was a voluptuous showstopper, the W113 was upright and boxy, almost severe. Paul Bracq’s coupe design was already very clean, but the roadster was a masterpiece of minimalism, stark in a way that only the cheapest or most expensive cars can really pull off. Whether you found it attractively restrained or just bland was a matter of taste, but it looked classy and more grown up than the 190SL, which had always had a vaguely cutesy air.

Mercedes 250SE (W111) coupe front 3q
The Mercedes W113’s cousin and platform-mate, the W111 coupe, seen here in later U.S.-spec 250SE form with the side marker lights mandated by federal safety regulations. The coupe was notably bigger than the roadster, stretching 192.1 inches (4,880 mm) on a 108.3-inch (2,750mm) wheelbase, and was considerably more expensive. (author photo)

Structurally, the W113 roadster had a great deal in common with the Mercedes 220SE coupe and rode a modified version of the same floorpan. The roadster’s wheelbase was shortened from the coupe’s 108.3 inches (2,750 mm) to 94.5 inches (2,400 mm), but the W113 retained the coupe’s 58.5-inch (1,482/1,484mm) tread width. Thanks to the wider track and squared-off fenders, the W113 looked bigger than the 190SL, but that was largely illusory: In fact, the new roadster was only 0.8 inches (20 mm) wider than the four-cylinder SL, although the W113 was 2.7 inches (70 mm) longer overall, probably to allow the installation of the M127 six without the firewall modifications required by the stillborn W127.

Although the W113 was described as a roadster to distinguish it from the 220SE cabriolet, in standard form the sports car was a proper convertible with wind-up windows and a well-padded top that stowed beneath a folding metal tonneau cover. Optional was the W113’s most distinctive and controversial styling feature: the so-called “Pagoda” hardtop. Based on a concept Barényi had developed and patented in the mid-fifties, the hardtop was concave, higher along its outer edges than in the center. The design had some practical advantages, including greater load-bearing strength, but it was none too aerodynamic,and even some Daimler-Benz engineers and executives were dubious about its aesthetics. Chief body engineer Karl Wilfert was not troubled by the love-it-or-hate-it reactions, arguing (correctly) that the Pagoda roof would become a conversation piece and the defining detail of the W113’s design.

1970 Mercedes 280SL (W113) Pagoda hardtop
The Pagoda hardtop, seen here on a 1970 Mercedes 280SL. The hardtop was fairly tall, with big windows for easier entry and exit and narrow pillars for expansive visibility — a great improvement over the 190SL’s optional hardtop. Unfortunately, the Pagoda roof was heavy (101 lb/46 kg, compared to about 45 lb/20 kg for the 190SL hardtop), which made it very cumbersome to remove. Chrome roof rails were optional on German SLs, but we believe they were standard on U.S. cars. (author photo)

220 to 230

Except for the steering wheel and instrument cluster, the relationship between the W113 roadster and the 220SE coupe was not obvious, but there was considerable kinship under the skin. The roadster’s recirculating ball steering and independent suspension were substantially the same as the coupe’s: a conventional double wishbone layout in front, still lacking ball joints, and suspended with coil springs and an anti-roll bar, and Mercedes’ now-familiar Eingelenkpendelachse system in back, with trailing arms, low-pivot swing axles, coil springs, and an auxiliary transverse coil spring acting as a camber compensator. The main departures from the coupe were 14-inch wheels, radial tires, and a faster steering ratio.

Mercedes 230SL (W113) wheel and tire
The Mercedes 230SL initially had 5.5Jx14 wheels, changed in 1964 to 6.0Jx14, but all W113s used 185HR14 tires, which were considered fairly racy stuff in 1963; most contemporary radials had section widths in the 155 to 165mm range. Although late 300SL roadsters had four-wheel discs, the 230SL used the same brakes as the 220SE: 10-inch (253mm) Girling discs and 9-inch (230mm) finned ATE aluminum drums with a standard vacuum servo. However, the roadster had a dual-circuit brake system, a safety feature not added to the coupe and cabriolet until months after the W113’s introduction. (author photo)

The W113’s commonality with the W111 coupe had both pros and cons. On the plus side, the roadster’s body was impressively stiff, with a solidity that would embarrass some open cars designed 25 or 30 years later. Like the W111/W112 cars, the W113 also had front and rear crumple zones to protect the occupants in a collision, a very novel feature for a sports car of this period. The roadster’s cabin was also roomy for a close-coupled two-seater; a single transverse rear seat was optional to make the roadster into a 2+1.

The major downside was weight. With its smaller dimensions and aluminum doors, hood, and decklid, the roadster was about 250 lb (115 kg) lighter than the 220SE coupe, but still weighed over 2,900 lb (1,315 kg) with a full tank of fuel — and that didn’t include the 101 lb (46 kg) hardtop. A fully equipped W113 was a good deal heavier than the E-type and only about 100 lb (45 kg) lighter than a Corvette Sting Ray.

The W113’s mass led to last-minute second thoughts about its engine. Originally, it was to share the 220SE’s 2,195 cc (134 cu. in.) six, but Uhlenhaut decided that to be competitive in the marketplace, the sports car needed more than 120 PS (88 kW, 134 bhp). The result was a heavily revised M127.981 engine with a new cylinder head, bigger ports and valves, a higher compression ratio, and a revised camshaft. The block was also revised with an aluminum crankcase and wider cylinder bores, bringing displacement to 2,306 cc (141 cu. in.). Topping this off was the latest Bosch multiport fuel injection system with a separate injector for each cylinder, positioned in the intake port almost directly above the valve.

M127 engine in Mercedes 230SL (W113), © 2012 Herranderssvensson (Anders Svensson) (CC BY-SA 3.0 Unported)
Like most Mercedes sixes of this vintage, the M127.981 engine had an aluminum head and an iron block, although the 230SL used an alternator instead of a conventional generator, a first for a regular-production German car. The paired tubes leading to the cylinder head are intake runners, designed to provide a resonance supercharging effect at mid-range speeds. (Photo: “M127 right” © 2012 Herranderssvensson; resized 2013 by Aaron Severson and used under a Creative Commons Attribution-ShareAlike 3.0 Unported license)

The result of all this was a healthy increase in power, from 120 PS to 150 PS DIN (110 kW; 170 bhp SAE) at 5,500 rpm. Torque was also increased about 5%, to 144 lb-ft DIN (195 N-m; 159 lb-ft SAE gross) at a rather high 4,500 rpm. Both figures were a dramatic improvement from the 190SL, but still well short of the 300SL’s 225 PS (165 kW; 250 bhp SAE gross).

The larger engine provided the W113’s official name: 230SL, “230” from the engine capacity in deciliters and SL for “Super Leicht” — although calling the 230SL “Light” was probably stretching the point.

GENEVA

The Mercedes 230SL made its public debut at the Geneva Auto Show in March 1963, although Mercedes-Benz PR officials also rented a small French racing circuit just across the border to ensure that journalists would have the chance to drive as well as see the new car.

1964 Mercedes-Benz 230SL (W113) front 3q © 2009 Spurzem - Lothar Spurzem (CC BY-SA 2.0 Germany)
A European Mercedes 230SL, distinguishable by its Lichteinheiten integrated headlight/foglamp units, which were similar to those of the W111 sedan and coupe and not permitted by contemporary U.S. lighting laws. This car’s rear wind deflector is not a period accessory, but the body-colored hubcaps are. (Photo: “MB 230 SL, Bj. 1964, Front (2009-05-01)” © 2009 Spurzem – Lothar Spurzem; resized and used under a Creative Commons Attribution-ShareAlike 2.0 Germany license)

It was immediately clear that despite its weight, the 230SL was a great step forward from the 190SL in straight-line performance. Although the factory’s 124 mph (200 km/h) claimed top speed was slightly optimistic, the 230SL was capable of 120 mph (193 km/h) or better. The 0-60 mph (0-97 km/h) sprint took around 10 seconds with manual transmission, a bit longer with automatic. (Uhlenhaut insisted the automatic SL was just as quick as the manual, but that claim was not supported by independent testers.) Either way, the 230SL was about 3 seconds quicker to 60 mph (97 km/h) than the 190SL and might have been quicker still with different gearing; both available transmissions suffered awkwardly spaced ratios that exposed the engine’s shortage of low-end torque.

Nonetheless, the 230SL was no match for the now-discontinued 300SL or for the Sting Ray and E-type, either of which could simply walk away from the Mercedes. In fact, the 230SL was only slightly quicker than the big 300SEL sedan, which had a commodious back seat and air suspension. There was certainly nothing wrong with the 230SL’s performance, which was brisk by European standards, but it suggested that Mercedes was deliberately opting not to vie with high-end sports car rivals.

Mercedes 230SL (W113) front
U.S.-spec Mercedes W113 roadsters did not use the Lichteinheiten lights of European cars, substituting sealed beam headlights, which were then required by federal law. (This 230SL appears to have the lights from a post-1967 car, with bigger turn signal lenses than the original units.) The W113’s comparatively upright stance made it significantly less aerodynamic than the 190SL or 300SL coupe, with an unimpressive 0.52 Cd. We have no figures for frontal area, but with the W113’s taller windscreen and blunter front fenders, we suspect its total drag area is substantially greater than that of its predecessors. The payoff, of course, was in superior visibility, easier entry/exit, and excellent crosswind stability. (author photo)

If the 230SL was not among the first rank in acceleration or top speed, its roadholding was another matter. The W113’s suspension was softer and less sophisticated than an E-type’s, and its ultimate limits were not extraordinary, but it could be driven hard over unfamiliar real-world roads with considerable assurance. With relatively low spring rates, lots of sprung weight, and a rigid body structure, the roadster also provided a remarkably civilized ride, particularly given its short wheelbase. In contrast, many small sports cars of the time handled little better and suffered a punishing ride on anything but a completely smooth road.

Another point in the 230SL’s dynamic favor was the optional power steering. Its availability raised eyebrows with critics — power steering was rarely offered on sports cars in those days, and even Corvette buyers seldom ordered it — but the 230SL’s power steering put the manual setup to shame, offering a faster ratio and less effort with no noticeable sacrifice in precision or feel.

THE MERCEDES AUTOMATIC TRANSMISSION

If the Mercedes 230SL fell short of its mission as a relaxed and unflappable cruiser, the culprit was the optional automatic transmission, announced at launch but not actually catalogued until later in the year.

Like most elements of the W113, the transmission was shared with the W111 and W112, where it had become available in late 1961. Designed by Hans-Joachim Förster, it had four forward speeds and used a two-element fluid coupling rather than a torque converter. The Mercedes automatic was frequently compared to GM’s early single-coupling Hydra-Matic, but the similarities were superficial. The Mercedes unit weighed about half as much as the older GM automatic, used only two planetary gearsets to Hydra-Matic’s three, and drove its fluid coupling impeller directly rather than routing power through the front planetary gearset.

The design nonetheless flew in the face of contemporary American thinking on automatic transmissions, which increasingly favored three speeds supplemented by a torque converter for added flexibility. Mercedes rejected that approach, presumably in the interests of maximum efficiency; the engineers claimed the lightweight automatic consumed only 8 hp (6 kW). Shift quality was firm but not lightning-fast, probably for the sake of band/clutch longevity. The staggered shift gate (which would be much imitated in the years to come) allowed full manual control of second and third gears, either of which could be held all the way to redline.

If you treated the automatic as a sort of semi-manual gearbox that could shift for itself when required, it worked reasonably well. Where it performed less adroitly was in gentler driving, where it tended to shift with the same sort of jerk GM had spent millions of dollars engineering out of the Hydra-Matic. This was compounded by the widely spaced ratios, which made for big changes in engine speed with each shift.

1964 Mercedes 230SL (W113) interior © 2009 Spurzem - Lothar Spurzem (CC-BYSA 2.0 Germany)
Even the earliest Mercedes W113 roadsters had a padded dashboard and visors, although additional modifications were eventually required to satisfy U.S. safety regulations. The steering wheel, with its padded circular boss, was much criticized when these cars were new, with reviewers calling it old-fashioned, but it has a certain charm that the more practical all-black wheels of the seventies lack. Leather upholstery was optional, but most W113s had MB-Tex leatherette. (Photo: “MB 230 SL, Bj. 1964, Armaturenbr (2009-05-01)” © 2009 Spurzem – Lothar Spurzem; resized and used under a Creative Commons Attribution-ShareAlike 2.0 Germany license)

An added annoyance was the fact that the automatic would only start in first if you floored the throttle or moved the shifter to ‘2’ — which was tempting, since few Mercedes engines of the time had enough torque to make a second-gear start anything other than lethargic. Even with a full-throttle, first-gear launch, the transmission would automatically upshift to second at 28 mph (45 km/h), dropping engine speed about 2,000 rpm in the process. (Admittedly, the four-speed manual transmission was not a great improvement, with an even shorter first gear (4.42:1), widely spaced ratios, long throws, and less-than-satisfying shift action.)

Mercedes would eventually adopt a three-speed torque converter automatic with a Simpson gearset like the Chrysler TorqueFlite or GM’s new Turbo Hydra-Matic, but not until the early 1970s, and not on the W113. In the meantime, the automatic represented a minor but sometimes irritating lapse in the 230SL’s otherwise polished manners.

A NEW (THREE-POINTED) STAR

Initial reviews of the Mercedes 230SL were generally positive. It probably helped that contemporary critics were not overly attached to either of the W113’s predecessors. The press had always been at best lukewarm about the 190SL, and there was a general acknowledgment that whatever its pedigree, the 300SL was past its sell-by date.

Except for the Pagoda hardtop, which provoked a few strong reactions both pro and con, many early reviewers politely sidestepped judgment of the 230SL’s aesthetic virtues while praising its well-trimmed interior and high standard of fit and finish. Similarly evaded was the matter of the SL’s middling acceleration, usually deflected with praise of the car’s roadholding and ability to maintain high average speeds without fuss.

Mercedes 230SL (W113) front 3q
Despite its softer ride, the Mercedes W113 actually handled better than did the old 300SL, thanks in large part to a much wider track (4 inches/100 mm wider in front, 2 inches/50 mm wider in back) and (comparatively) fat radial tires. The main shortcomings of the W113’s suspension were the need for frequent chassis lubrication (reduced somewhat on the 280SL) and excessive nosedive under braking, exacerbated by an overzealous vacuum booster. (author photo)

Mostly, the press recognized the 230SL as a well-engineered, quality product: It felt like money, which was appropriate because it was not at all cheap. In West Germany, list price was 20,600 DM (equivalent to $5,150) in roadster form, around 15% more than a 190SL. A fully loaded 230SL with both tops, automatic, power steering, and other options could top 25,000 DM (about $6,250). Admittedly, the 230SL was less expensive than a 220SE cabriolet and substantially cheaper than the old 300SL roadster, but that was hardly a bargain price. It was a similar story in the U.S., where the 230SL’s base price was around $6,500 POE, about $1,000 more than an E-type or fuel-injected Sting Ray.

Perhaps hoping to bolster the 230SL’s sporting credentials, Karl Kling, the manager of the very successful Mercedes rally team, added the roadster to the team roster. In late August, a single 230SL, driven by 1962 European Rally Champion Eugen Böhringer and co-driver Klaus Kaiser, entered the 1963 Spa-Sofia-Liège Rally and won outright. Of course, the rally car was not quite stock, using a bored-out engine with about 165 PS (121 kW), a beefed-up suspension, and 15-inch wheels, but the win was a testament to the inherent ruggedness of the W113 platform.

Mercedes trumpeted the victory in its advertising, but the 230SL was never as important to the rally team’s efforts as the 220SE and 300SE sedans, which garnered the lion’s share of the team’s eye-opening array of triumphs. The 230SL’s rally career was also short-lived. Several 230SLs ran in the 1964 Spa-Sofia-Liège Rally, but this time the victory went to an Austin-Healey 3000 driven by Rauno Aaltonen and Tony Ambrose. Mercedes withdrew from rally competition at the end of the 1964 season, but the 230SL had one final factory-backed outing at Greece’s 1965 Acropolis Rally, although a navigational error consigned driver Dieter Glemser and co-driver Martin Braungart to a fifth-place finish.

All this made little difference to buyers, who responded strongly to the 230SL from the start. The 230SL had its limitations, but, as we noted at the outset, there were almost no direct alternatives. There were precious few luxury cars in that era that could match the SL’s road manners, and even those that approached them, like the Jaguar Mark X and Mercedes 300SE, were far less sporting in flavor. There were cheaper sports cars that could outperform the 230SL, but none was as comfortable or as easy to drive. (Just clambering into the low-slung E-type, with its wide sills, was a test of coordination for middle-aged owners.) As a result, average annual 230SL sales were at least 50% better than the 190SL had ever done. Demand exceeded Daimler-Benz’s comparatively limited capacity, leading to lengthy waiting lists.

Mercedes 230SL (W113) rear 3q
In Germany, the Mercedes W113 was offered as a single model with the Pagoda hardtop as an option, initially priced at 1,100 DM (about $275). If you ordered the hardtop and didn’t plan to remove it often (or didn’t have anywhere to store it), you could delete the soft top mechanism for a credit (initially 750 DM, around $187). In some markets, the three variations (soft top, hardtop, both tops) were catalogued as separate models, typically dubbed roadster, coupe, and coupe-convertible, respectively. A 250SL with the soft top deleted could be ordered with a small rear bench seat, a combination sometimes called the California roadster or California coupe.

That popularity allowed the 230SL roadster to remain in production for four years with almost no cosmetic changes, although there were various mechanical refinements, including wider wheels (from 5.5J to 6J), a relocated spare tire, and a larger fuel tank (expanded from 17.2 gallons/65 liters to 21.7 gallons/82 liters).

One of the most intriguing was the addition in March 1966 of an optional five-speed gearbox. Made by ZF, it had a taller first gear than the Mercedes four-speed and an overdrive fifth gear for more relaxed cruising. (There was also a close-ratio gearset with a direct top gear, but we don’t know if any were installed in W113s.) While the five-speed sounded ideal on paper, its shift quality was nothing special, and it was both hard to obtain and quite expensive: 1,200 DM (around $300) in Germany, a hefty $464 in the U.S. It was generally available only by special order, and is very rare today.

MERCEDES 250SL

In August 1965, about two years after the introduction of the 230SL, the W111 and W112 sedans were replaced by the new W108 and W109 series. The W111 and W112 two-door models, which the new sedans strongly resembled, continued with few changes, but all now had larger four-wheel vented disc brakes and a new 2.5-liter (152 cu. in.) six.

Called M129 in fuel-injected form, the new engine had a substantially new block with seven main bearings for greater smoothness. It combined the 82mm (3.23-inch) bore of the 230SL’s 2,306 cc six with a longer 78.8mm (3.10-inch) stroke for a total displacement of 2,496 cc (152 cu. in.). The cylinder head was similar to the 230SL’s, albeit with bigger valves, and Bosch multiport injection was again specified. Peak output was the same 150 PS DIN (110 kW, 170 bhp SAE) as the 230SL’s 2,306 cc engine, albeit with 159 lb-ft of torque (216 N-m, 174 lb-ft SAE). An oil-to-water oil cooler and a viscous-coupling fan (which became optional on the 230SL in 1966) were also included.

Mercedes 250SE (W111) cabriolet front 3q
The two-door Mercedes W111 models received the M129 engine and four-wheel discs brakes for the 1966 model year; this is a European 250SE cabriolet. We have to admit we’re not sure why the W113 lagged so far behind, particularly since we assume production rationalization was a major motivation for the introduction of the 250SL. (author photo)

It was more than a year before Mercedes began installing the new engines and brakes in the SL. The revised car, now called 250SL, debuted in Europe in late February 1967. Except for its engine and brakes, the 250SL was very similar to the late 230SL — a point Mercedes advertising took pains to mention — but the four-speed manual transmission had slightly taller ratios and the axle ratio was lowered from 3.75 to 3.92:1. A taller 3.69 axle was now available by special order.

In Germany, the bigger engine and four-wheel disc brakes brought the 250SL’s base price to 21,600 DM (equivalent to about $5,400). U.S. cars cost about $300 more than the last 230SL. A fully loaded U.S. 250SL now topped $8,000 — not quite in the realm of exotics like Aston Martin, but in the same range as the new FWD Cadillac Eldorado.

1967 Mercedes-Benz 250SL (W113) front 3q © 2012 Berthold Werner (CC BY-SA 3.0 Unported)
The Mercedes 250SL was not the fastest sports car on the road in 1967, but did have top-flight brakes: vented discs all around with diameters of 10.7 inches (270 mm) in front and 11.0 inches (280 mm) in back; 430 sq. in. (2,775 sq. cm) of swept area; a pressure-limiting valve to reduce the chances of locking the rear brakes; and integral drum-type parking brakes. (Photo: “Mercedes-Benz 250 SL W 113 2012-07-15 14-55-26” © 2012 Berthold Werner; resized 2013 by Aaron Severson and used under a Creative Commons Attribution-ShareAlike 3.0 Unported license)

The 230SL remained in production through early 1967 and was still on sale for some time after that, particularly in the U.S., where the 250SL wasn’t introduced until April and wasn’t available in substantial numbers until summer. Midway through the year, the 250SL received an interior makeover and other minor changes to comply with the new U.S. federal safety standards scheduled to take effect January 1.

Otherwise, the 250SL was not easily distinguished from its predecessor unless you were close enough to read the emblems. The extra 190 cc (12 cu. in.) still didn’t make the six particularly muscular at low speeds, but its additional torque meant that a 250SL with automatic was now about as quick as a 230SL with manual transmission, a modest but useful improvement. The M129 was also smoother than was the M127, although some owners complained that the bigger six was prone to fouling its spark plugs in slow traffic.

Nonetheless, the 250SL was well received by critics. Like the 230SL, it didn’t really excel in any single area, but it offered a unique blend of virtues wrapped in an aura of quiet but unmistakable affluence that provoked period automotive writers — and no doubt many buyers and observers — to fits of covetous eloquence.

MERCEDES 280SL

The 250SL was in a sense an interim model: In late 1967, Mercedes switched from the M129 six to the bigger M130, also used in the latest W108/W109 sedans. The new engine retained the M129’s stroke, but had re-spaced bore centers, allowing the bore to be expanded from 82 to 86.5 mm (3.23 to 3.41 inches) for a total displacement of 2,778 cc (170 cu. in.). Adding this engine to the roadster created the third and final iteration of the W113 platform: the Mercedes-Benz 280SL roadster.

1970 Mercedes 280SL (W113) M130 engine
On U.S. cars, the Mercedes 280SL’s M130 engine was basically the same as the one in the 280SE models, with 160 PS (118 kW) and 177 lb-ft (240 N-m) of torque (DIN; 180 bhp and 193 lb-ft SAE gross). European cars had a hotter camshaft, giving 170 PS (125 kW; 195 bhp SAE). While the M130 was more powerful than the M129, some testers and owners complained that it was still susceptible to plug-fouling in traffic. (author photo)

The new engine’s additional power and torque were blunted somewhat by the W113’s steadily increasing weight, which now approached 3,200 lb (1,450 kg) with automatic and power steering, but the 280SL was nonetheless the quickest W113. With 23% more torque than the original 230SL, an automatic 280SL was now capable of 0-60 mph (0-97 km/h) times in the mid-9s, although top speed was little changed, limited mainly by gearing. The ZF five-speed was still nominally available, but not common. It disappeared from U.S. options lists in 1970, although it was catalogued in Germany to the end of production.

Depending on your point of view, the 280SL felt either more mature or a trifle lazier than the early 230SL. The suspension was also noticeably softer (thanks in part to the adoption of rubber suspension bushings to reduce the need for chassis lubrication), although by this point nobody except the occasional errant journalist expected the W113 to drive like a Corvette. The engine was less eager to rev as well, although with an extra half-liter of displacement, there was also less need to.

One might have expected that by 1969 the W113 would be in its declining years, especially considering that the exterior styling had changed almost not at all in more than five years, but based on the sales figures, the SL had found its niche. 1969 production topped 8,000 units — not a lot in absolute terms, but more than double the total 1955–1963 production of both the 300SL coupe and roadster.

1970 Mercedes 280SL (W113) front 3q
While the European Mercedes 280SL retained the previous 3.92 axle (with 3.69 or 4.08 ratios optional), U.S. cars initially had the 4.08 axle as standard, perhaps as a concession to low American speed limits. With either four-speed transmission, that meant about 4,000 rpm at 70 mph (113 km/h) in high, a figure more befitting a Triumph Spitfire than an $8,000 luxury touring car. Late U.S. cars belatedly reverted to the 3.92 ratio. (author photo)

One reason for the 280SL’s continued strong sales was that by the late sixties affluent American buyers were discovering Mercedes in growing numbers. In 1964, toward the end of Daimler-Benz’s distribution relationship with Studebaker, Mercedes sold around 11,000 cars in the U.S.; by 1970, Mercedes-Benz of North America was approaching the 30,000-a-year mark. The 280SL represented a relatively small fraction of that total, but was something an intrepid dealer could sell to a customer who already had a Mercedes 300SEL or wanted to show up their golf partner’s 280SEL 3.5 coupe. Such buyers appreciated the W113’s build quality and durability, and were not troubled by its high maintenance costs or other minor foibles.

QUEST FOR POWER

Despite the Mercedes W113’s growing popularity, there was obvious room for improvement. The M130 engine still didn’t have an abundance of torque and was not especially quiet when pushed. In a drag race, the 280SL wasn’t far behind comparably priced American personal luxury coupes like the Cadillac Eldorado or Lincoln Mark III, but extracting such performance required more screaming 6,500 rpm manual upshifts than the average Mercedes owner was likely to tolerate. The automatic transmission, now ordered by more than 60% of customers, was short on finesse, considering the SL’s price and clientele, and still didn’t start in first, an irritation Mercedes had already addressed on the sedans. There was also a growing threat from BMW, whose new six-cylinder 2800CS coupe was aimed at the same market as the Mercedes 280SL.

1970 Mercedes 280SL (W113) interior
The Mercedes 280SL’s interior was mostly the same as the late 250SL’s, differing from the early 230SL mainly in minor details. Most were safety-related, but there were also improved seats and better lighting for minor controls. The W113 had decent but not outstanding heating and ventilation for the era, but there was no provision for factory air conditioning (although a Frigi-King or other hang-on unit could be added beneath the dash), a shortcoming addressed on the R107. (author photo)

In the summer of 1967, Erich Waxenberger tested at the Nürburgring a W113 test mule into which he’d stuffed the big M100 V-8 from the Mercedes 600 and 300SEL 6.3 sedans. The 6,332 cc (386 cu. in.) V-8, which had 250 PS (184 kW; 300 bhp SAE gross) and 370 lb-ft (502 N-m; 435 lb-ft SAE) of torque, made the SL a real hot rod, but jamming the enormous M100 into the W113’s engine bay wasn’t easy, and the V8’s substantial extra weight spoiled the roadster’s handling. The project was subsequently abandoned and the test mule scrapped.

The following year, Daimler-Benz engineers explored a more radical idea: creating several W113 prototypes powered by the M50F, a three-rotor Wankel rotary engine with 203 PS (149 kW). Since the W113 was nearing the end of its production life, there was little chance of a rotary W113 being offered for sale, but the M50F was seriously considered for the W113’s planned successor, which was designed with provision for the rotary engine.

A V-8 W113 would have been possible had Daimler-Benz been so inclined. In the fall of 1969, the S-Class sedans and 280SE coupe and cabriolet had received the new M116 engine, a 3,499 cc (214 cu. in.) SOHC V-8 with 200 PS DIN (147 kW; 230 bhp SAE gross) and 211 lb-ft (286 N-m; 231 lb-ft SAE) of torque The M116 was more compact and considerably lighter than the M100 — in fact, the smaller V8 was only a little heavier than the M130 six — so installing it in the W113 to create a “280SL 3.5” would probably not have been a difficult exercise.

1970 Mercedes 280SL (W113) rear 3q
It takes a sharp eye to distinguish the various iterations of the Mercedes W113 series. Late U.S. 250SLs and all U.S.-spec 280SLs had side marker lights and other lighting changes to comply with federal safety regulations, but otherwise, a late 280SL looks much like a 230SL. This 1970 has the standard steel wheels, but attractive Fuchs alloy wheels became available in 1969. (author photo)

Had the “Pagoda” line continued for a few more years, we assume Daimler-Benz would have offered such a car, which might well have been the most desirable W113. However, by the time such a car would have been ready, the W113’s successor, the R107 roadster, was very close to production, rendering the older car redundant.

W113 production ended in March 1971, although the 280SL remained on sale for the rest of the model year — mainly in the U.S., where the new R107 350SL was not introduced until August. Total W113 production was a respectable 48,912 units, including 19,831 230SLs, 5,196 250SLs and 23,885 280SLs. The six-cylinder Jaguar E-type still outsold the Mercedes, but the W113 figures weren’t bad at all considering the Mercedes-Benz cars’ much higher prices. The W113 also outsold the 190SL and 300SL combined, and was probably more profitable than either.

THE STATUS SYMBOL

The Mercedes R107, which bowed in 1971 as the 350SL, was an obvious and logical extension of the W113’s basic concept: bigger, heavier, and more modern inside and out, with new features like integral air conditioning. A V8 engine was now standard — the 3,499 cc (214 cu. in.) M116 for non-U.S. markets, the low-compression 4,520 cc (276 cu. in.) M117 for the confusingly badged American 350SL 4.5 — and U.S. cars came standard with a new and much smoother three-speed torque converter automatic. (The six-cylinder 280SL would be revived in some markets after the OPEC embargo, this time powered by a DOHC 2,746 cc (168 cu. in.) engine.)

Aesthetically, the R107 fell short of the W113’s uncluttered elegance, but the design had legs, surviving through 1989 in a bewildering number of variations. Its performance waxed and waned over the years, seldom with any great impact on its popularity. Like the Pagoda, it could be driven in a sports-car-like manner without embarrassing itself, but canyon-carving wasn’t really the point. We suspect that many buyers were attracted to the SL because it was rakish enough to earn envious stares at the country club or valet stand, but didn’t ask its owner to suffer for the privilege. The SL was not the sexiest or most exciting two-seater, but it gave away nothing to any competitor when it came to luxury or prestige.

1977 Mercedes 450SL (R107) front3q
Although the Mercedes W113 is commonly known as the “Pagoda,” the distinctive hardtop was also adapted for the R107 roadster, seen here in U.S. 450SL form. Although all U.S. R107s through 1980 used a 4,520 cc (276 cu. in.) V8, first-year federalized cars were badged 350SL 4.5, which was renamed 450SL the following year.

The SL-Class, as Mercedes now calls these cars, has remained true to that formula for 50 years, with great and undoubtedly lucrative success. Although the SL’s role has become clearer over time, there have been surprisingly few direct imitators, the most obvious probably being the Cadillac Allanté and XLR. Of course, there have been numerous sporty, luxurious coupes, like the BMW 6-Series and Jaguar XJ-S and XK, but those are closed four-seaters (which Mercedes also has), and not really the same thing. Given the stature and longevity of the SL, rivals may be missing a bet.

Still, the SL Class might never have gotten off the ground if the W113 had not been so adroitly executed. Its styling has aged remarkably well; while it obviously doesn’t look like a modern car, its purposeful simplicity and lack of ostentation still do it credit. It isn’t cheap to run, repair, or restore, but the W113 was built to last, and it’s better suited to modern traffic than many of its contemporaries. The term “classic” has been much abused in recent years, but we think the W113 is among the handful of postwar cars that can wear that label without irony.

FIN

NOTES ON SOURCES

Our sources included “Autocar road test 1998: Mercedes-Benz 300SE l.w.b.,” The Autocar 30 October 1964: 918-922; The Auto Editors of Consumer Guide, “1955-1963 Mercedes-Benz 190SL,” HowStuffWorks.com, 18 September 2007, auto.howstuffworks. com/ 1955-1963- mercedes-benz-190sl.htm, accessed 12 February 2013, and “Mercedes-Benz Sports Cars,” HowStuffWorks.com, 1 June 2007, auto.howstuffworks. com/ mercedes-benz-sports-cars.htm, accessed 5 February 2013; “Autos Abroad,” Car Life May 1963, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 2010), p. 35; “Autotest: Mercedes-Benz 280SL (2,778 c.c.),” Autocar 3 September 1970, reprinted in ibid, pp. 144-148; “Autotest: Mercedes-Benz 280SE automatic,” Autocar 18 June 1970, reprinted in Mercedes-Benz S Class & 600 Limited Edition 1965-1972, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 2006), pp. 76-80; Béla Barényi, “Motor Car Formed From a Base and a Top Section,” U.S. Patent No. 2,723,154, filed 7 January 1950, issued 8 November 1955, and assignor to Daimler-Benz AG, “Vehicle Top Structure,” U.S. Patent No. 3,233,937, filed 19 March 1963, issued 8 February 1966; Hansjörg Bendel, “Mercedes 230SL,” Road & Track Vol. 14, No. 10 (June 1963), reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 19-22; Stuart Bladon, “Road Impressions: Day out with the new Mercedes V8,” Autocar 2 April 1970, reprinted in Mercedes-Benz S Class & 600 Limited Edition 1965-1972, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 2006), p. 81; Martin Buckley, “Mercedes, Meet thy maker,” Classic & Sports Car August 2009, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 177-181; Bernard Cahier, “Road Test/10-63: Mercedes-Benz 230 SL,” Sports Car Graphic May 1963, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 31-34; Simon Charlesworth, “Restrained Decadence,” Classic Cars November 2008, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 182-188; Mike Covello, Standard Catalog of Imported Cars 1946-2002, Second Edition (Iola, WI: Krause Publications, 2001); Daimler AG, “A stylist with a strong sense of aesthetics and proportion: Friedrich Geiger” [press release], 28 March 2012; “Historical SLs in the wind tunnel” [press release], 18 June 2012, “Master of SL design: Bruno Sacco” [press release], 28 March 2012; “Mercedes-Benz, model range W 113, with eight-cylinder engine” [press release], 26 March 2012; “Mercedes-Benz SL, W113 series – the first sports car with a safety body” [press release], 26 March 2012; “The design of the Mercedes-Benz SL-Class” [press release], 28 March 2012; “The motor sport history of Mercedes-Benz” [press release]; “The rotary piston engine in Mercedes-Benz SL W113 and R107 experimental vehicles” [press release], 26 March 2012; and “Two biographies: Richard Seaman and Rudolf Uhlenhaut” [press release], 13 June 2007, media.daimler. com, accessed 14 February to 10 April 2013; “Prof. Dr.-Ing. h.c. Fritz Nallinger (Members of the Board of Management), n.d., www.daimler. com, accessed 10 April 2013, Daimler-Benz AG, “Mercedes-Benz Preisliste Nr. 3 für Personenwagen,” May 1964; “Mercedes-Benz Preisliste Nr. 14 für Personenwagen,” September 1963; and “Mercedes-Benz Preisliste Nr. 20 für Personenwagen,” May 1968; Richard Dredge, “Buying Guide: Mercedes ‘Pagoda’ 230-280SL 1963-1971,” Octane July 2008, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 189-192; Gavin Farmer, “1955-1963 Mercedes-Benz 190SL: Stuttgart’s Lost Classic,” Collectible Automobile Vol. 17. No. 5 (February 2001): 26-37; Gregor Gant, “Mercedes-Benz 230SL,” Autosport 18 September 1964, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 50-51; “Giant test: Fiat 2300S v. Mercedes 230SL,” Car December 1965, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 84-88; “Group Test No. 7: Extravagant two seaters,” Motor 7 September 1968, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 113-119; Andy Halibery, “Rudolf Uhlenhaut: Supreme engineer,” Motor Sport Retro, 10 April 2012, www.motorsportretro. com, accessed 14 February 2013; John Heilig, Mercedes-Benz SL (Sports Car Color History) (Osceola, WI: MBI Publishing Company, 1997); Martin Holmes, “Tony Ambrose: Champion rally co-driver,” The Independent, 26 January 2008, www.independent. co. uk, accessed 10 April 2013; Geoffrey Howard, “Getaway Merc,” Autocar 9 May 1968, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 100-101; “In memoriam Karl Wilfert,” Auto Motor und Sport 7/1976 (27 March 1976); International Money Fund, “Cooperation and reconstruction (1944–1971)” and “The end of the Bretton Woods System (1972–1981),” About the IMF: History, N.d., www.imf. org, last accessed 2 April 2014; John Katz, “1971 Mercedes-Benz 280 SL: Civilized Sports Car,” Special Interest Autos #162 (November-December 1997): 10-15, 56-58; Beverly Rae Kimes, The Star and the Laurel: The Centennial History of Daimler, Mercedes and Benz 1886-1986 (Montvale, NJ: Mercedes-Benz of North America, Inc., 1986); Tom Klockau, “Curbside Classic: 1963 Mercedes-Benz 230SL – Big Shoes to Fill,” Curbside Classic, 7 September 2012, www.curbsideclassic.com/ curbside-classics-european/ curbside-classic- 1963-mercedes-benz-230sl -big-shoes-to-fill/, accessed 13 February 2013; Bernd. S. Koehling, “The Mercedes Pagoda SL,” Squidoo, www.squidoo. com/ history-of-mercedes- the-pagoda-sl, accessed 14 February 2013, and “The MERCEDES Pagoda SL,” 2012, www.benz-books. com/ mercedes_history _230sl_w113.html, accessed 14 February 2013; Brian Long, Mercedes SL W113 Series (Dorchester, England: Veloce Publishing Plc., 2011), and Mercedes-Benz SL and SLC 107 Series, 1971 to 1989 (Dorchester, England: Veloce Publishing Plc., 2010); Karl Ludvigsen, “Mercedes Builds a Brain Box,” Car and Driver Vol. 7, No. 6 (December 1961): 40-41, 89; Tom McCahill, “The Mercedes-Benz 190 SL,” Mechanix Illustrated April 1956, pp. 98-101, 202, and “Mercedes-Benz 230SL,” Mechanix Illustrated August 1965, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 74-75; “Mercedes,” Road Test January 1971, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, p. 157; “Mercedes Benz,” Motor 24 June 1967, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, p. 95; “Mercedes-Benz 190SL Roadster (121) Technical Specifications,” Unique Cars and Parts, n.d., www.uniquecarsandparts. com.au, accessed 13 February 2013; “Mercedes-Benz 230-SL,” Car and Driver Vol. 8, No. 12 (June 1963), reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 24-30; “Mercedes-Benz 230-SL,” Car and Driver 1966, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, p. 79; “Mercedes-Benz 230SL 2,306 c.c.,” The Autocar 4 September 1964, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 38-42; “Mercedes-Benz 230-SL Automatic,” Road & Track Vol. 17, No. 4 (November 1965), reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 61-64; “Mercedes-Benz 230SL Automatic 2,306 c.c.,” The Autocar 2 October 1964, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 43-45; “Mercedes-Benz 230SL (113) Technical Specifications,” Unique Cars and Parts, n.d., www.uniquecarsandparts. com.au, accessed 13 February 2013; “Mercedes-Benz 250SL,” Car and Driver Vol. 13, No. 2 (August 1967), reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 90-94; “Mercedes-Benz 250SL,” Car South Africa May 1967, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, p. 99; “Mercedes Benz 250SL,” Foreign Car Guide December 1967, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 102-105; “Mercedes-Benz 250SL,” Road & Track Vol. 18, No. 9 (May 1967), reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, p. 89; “Mercedes-Benz 250SL (113 A) Technical Specifications,” Unique Cars and Parts, n.d., www.uniquecarsandparts. com.au, accessed 13 February 2013; “Mercedes-Benz 280SL,” Popular Imported Cars March 1971, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 165-170; “Mercedes-Benz 280 SL,” Road & Track Vol. 19, No. 12 (August 1968), reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 109-112; “Mercedes-Benz 280SL (113 E28) Technical Specifications,” Unique Cars and Parts, n.d., www.uniquecarsandparts. com.au, accessed 14 February 2013; “Mercedes 250 SL,” Road Test 1968, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 129-131; “Mercedes 280 SL,” Road Test 1968, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 141-143; “Mercedes 280 SL,” Road Test January 1970, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 154-156; “Mercedes S-Type,” Popular Classics June 1991, reprinted in Mercedes-Benz S Class & 600 Limited Edition 1965-1972, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 2006), pp. 130-131; Laurence Meredith, Original Mercedes SL (Bideford, Devon: Bay View Books/MBI Publishing Company, 1996); “New ‘upper class’ Mercedes,” Motor 14 August 1965, reprinted in Mercedes-Benz S Class & 600 Limited Edition 1965-1972, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 2006), pp. 6-8; “1963-1971 Mercedes-Benz 230SL, 250SL & 280SL,” Road & Track Vol. 37, No. 3 (October 1985), reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, p. 171; Eric Nielssen, “Six Luxury Cars: a view from the Automotive Engineering Side,” Car and Driver Vol. 11, No. 1 (July 1965), 26–31, 62–65, 75; Andrew Noakes, “Beauty and the Best,” Classic & Sports Car August 2006, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 172-176; Jan P. Norbye and the Auto Editors of Consumer Guide, BMW: Bavaria’s Driving Machines (Skokie, IL: Publications International, Ltd., 1984); David Owen, “Star Performer: 230SL,” World’s Faster Sports Cars 1965, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 52-55; John R. Olsen, ed., Collecting the Mercedes-Benz SL 1954-1993 (Minneapolis, MN: The SL Market Letter, Inc., 1993); Pagoda SL Group Technical Manual, www.sl113. org/ wiki/, accessed 13 February 2013; Simon Read, “Tales of the 300SL,” Automobile Quarterly’s Great Cars & Grand Marques, ed. Beverly Rae Kimes (Princeton, NJ: Automobile Quarterly/Bonanza Books, 1979), pp. 88-97; André Ritzinger, “Mercedes 190SL 1955-1963,” RitzSite, n.d., www.ritzsite. nl/ 190SL/ 01_190SL.htm, accessed 12 February 2013, “Mercedes 300 SL 1952-1963,” RitzSite, n.d., www.ritzsite. nl/300SL/01_300SL.htm, accessed 12 February 2013, and “Mercedes 280 SL – 1968,” RitzSite, n.d., www.ritzsite. demon.nl/ 280SL/ MB280SL.htm, accessed 12 February 2013; André Ritzinger and Naj Jesani, “1964 Mercedes 230 SL Pininfarina coupe: the mystery car,” RitzSite, n.d., www.ritzsite. demon.nl/ 230SLPF/ 01_SLPF.htm, accessed 12 February 2013; André Ritzinger and Derek Jettmar, “Modified 1968 Mercedes 280 SL: 6.3 litre muscle car,” RitzSite, n.d., www.ritzsite. nl/ 280SL63/ 01_SL63.htm, accessed 12 February 2013; “Road & Track Comparison Test: Four Luxury GTs,” Road & Track Vol. 20, No. 10 (June 1969), reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 134-139; “Road Test: Mercedes-Benz 230SL,” Sporting Motorist August 1965, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 76-78; “Road Test: Mercedes-Benz 250SL,” Sports Car Graphic August 1967, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 96-98; “Road Test No. 23/65: Mercedes-Benz 230SL,” Motor 5 June 1965, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 56-60; “Road Test — The Mercedes-Benz 230SL,” Motor Sport June 1965, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 65-67; Bill Sanders, “Mercedes-Benz 280 SL: The Limousine Sports Car,” Motor Trend Vol. 20, No. 10 (October 1968), reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 132-133; Rainer W. Schlegelmilch and Hartmut Lehbrink, Mercedes (Cologne, Germany: Könemann VG mbH, 1997); Eberhard Seifert, “A New Star: Mercedes 230-SL,” Road & Track Vol. 14, No. 9 (May 1963), reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 6-8; Reinhard Seiffert, “Test Mercedes-Benz 230 SL,” auto motor und sport 21/1963 (19 October 1961): 18–23; Jerry Sloniger, “Mercedes Benz 280 SL,” Foreign Car Guide October 1968, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 122-123, and “Most Mercurial Merc,” Wheels October 1968, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 126-128; Heinz Thiemann, “Two Surprises from Stuttgart,” Sports Car World May 1963, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 11-13; Bill Tuckey, “The Mighty Mercedes 230SL,” Sports Car World April 1965, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 68-72; “Two from the Top,” The Autocar 29 March 1963, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 14-16; “230SL Appetizer,” Sporting Motorist March 1965, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, p. 49; “230SL Replaces the 190SL,” Motor 13 March 1963, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 9-10; “Type 230 SL Pagoda – Mercedes,” Oldtimer, n.d., weboldtimer. com, accessed 13 February 2013; “Used Car Test: 1968 Mercedes-Bezns 280SL automatic No. 335,” Autocar 14 October 1971, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 160-161; Maarten van Eijck, The Heckflosse Homepage, n.d., www.heckflosse. nl, accessed 14 February 2013; Ralph Vonderstein, Heckflosse, n.d., www.heckflosse. de, accessed 13 February 2013; Ron Wakefield, “Road & Track Owner Survey: 230/250/280SL Owner Survey,” Road & Track Vol. 21, No. 12 (August 1970), reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 149-153; Ian Webb, “Exoticars: Mercedes-Benz 280SL,” Custom Car December 1971, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 158-159; the Wikipedia® entries for the Bretton Woods (en.wikipedia.org/wiki/Bretton_Woods_system, accessed 8 April 2013); Bruno Sacco (en.wikipedia.org/wiki/Bruno_Sacco, accessed 14 February 2013), Friedrich Geiger (en.wikipedia.org/wiki/Friedrich_Geiger, accessed 7 April 2013), Fritz Nallinger (en.wikipedia.org/wiki/Fritz_Nallinger, accessed 14 February 2013), Karl Wilfert (en.wikipedia.org/wiki/Karl_Wilfert, accessed 14 February 2013), Mercedes-Benz 300SL (en.wikipedia.org/wiki/Mercedes-Benz_W198, accessed 14 February 2013), Mercedes-Benz W113 (en.wikipedia.org/wiki/Mercedes-Benz_W113, accessed 12 February 2013) and the equivalent German Wikipedia page (de.wikipedia.org/wiki/Mercedes-Benz_W113, accessed 13 February 2013), the Mercedes-Benz W114 (en.wikipedia.org/wiki/Mercedes-Benz_W108, accessed 11 April 2013), the Mercedes-Benz M130 engine (en.wikipedia.org/wiki/Mercedes-Benz_M180_engine, accessed 9 February 2013), and Paul Bracq (en.wikipedia.org/wiki/Paul_Bracq, accessed 14 February 2013); Karl Wilfert and Béla Barényi, assignors to Daimler-Benz AG, “Vehicle Roof Convexly and Concavely Curved With Rim Therefor,” U.S. Patent No. 3,239,269, filed 25 September 1962, issued 8 March 1966; Gordon Wilkins, “A Flier from the Fatherland,” Sports Car World December 1963, reprinted in Mercedes 230SL – 250SL – 280SL Ultimate Portfolio 1963-1971, pp. 36-37; “W113, W111 Preisliste Nr. 8,” 24 January 1972, www.meinbenz. de, 12 March 2013; Jim Wright, “For the first time in history, the Corvette Sting Ray is …” Motor Trend Vol. 15, No. 5 (May 1963), reprinted in Corvette Sting Ray Gold Portfolio 1963-1967, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 1990), pp. 18-23; Brock Yates, “Viewpoint: Mercedes-Benz 250,” Car and Driver Vol. 14, No. 2 (August 1968), reprinted in Mercedes-Benz S Class & 600 Limited Edition 1965-1972, ed. R.M. Clarke (Cobham, England: Brooklands Books Ltd., ca. 2006), 52-55; and an email to the author from Eric Buckle, 13 February 2013.

Some historical exchange rate data for the dollar and Deutschmark came from Lawrence H. Officer, “Exchange Rates Between the United States Dollar and Forty-one Currencies” (2011, MeasuringWorth, https://www.measuringworth.org/exchangeglobal/, used with permission). Exchange rate values cited in the text represent the approximate equivalency of German and U.S. currency at the time, not contemporary U.S. suggested retail prices, which are cited separately. Please note that all exchange rate equivalencies cited in the text are approximate and are offered solely for the reader’s general reference; this is an automotive history, not a treatise on currency trading or the value of money, and nothing in this article should be taken as financial advice of any kind!


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  1. Aaron,

    Thanks for the mention as a source. Glad I could assist! As a former owner of a 190 Heckflosse, I really enjoyed the write-up!

    Keep up the excellent work!

    EB

  2. Thanks for another good read.

    In the second paragraph of the 250SL section is this line:
    “…combined the 82mm (3.23-inch) stroke of the 230SL’s six with a longer 78.8mm (3.10-inch) stroke for a total displacement of 2,496 cc (152 cu. in.).”

    You’ve got two numbers listed as the stroke. Am I correct in guessing the 82mm number is the bore of the engine?

    1. Oops! Yes, that should have been "the 82mm (3.23-inch) bore."

      Thanks for the correction — I’ve amended the text.

  3. Thorough and judicious as always, you capture perfectly the virtues and drawbacks of the113 with a fine sense of historical context and the competition.

    I may be wrong, but I believe the dark blue 230SL you show has replacement US headlight frames from a 280, with the much larger orange turn signal lens, instead of the narrow orange strip at the bottom–a not uncommon thing to see, as are replacement tail lights with orange blinkers, instead of the full red lenses. Not nit-picking here–in the eternal restorers’ debate between aesthetics and accuracy, I am an aesthete. I have a 67 pseudo-250SL: originally a 230 (as VIN indicates), but a replacement block from previous owner from a 250SE. He also put on a 250SL trunk badge, which is one of many hard-to-find-so-absurdly-expensive parts for 113’s. I’ve further mucked it up for purists by installing European headlight units on an originally US car, but they express the clean original Bracq design much better to my mind.

    Market values for the 250SL (real, not pseudo, like mine) remain oddly less than one would think, given their short production run, and what at least some consider its combination of superior power to the 230 and lighter weight and less squishy suspension than the 280. The latter seems to have been modified with more of an eye to the US market, particularly in the increasing prevalence of automatics over manual gearboxes. With the 107 firmly aimed at American tastes, the manual all but vanished from US-spec models, and Mercedes certainly cashed in. There’s an interesting (arguably saddening) history to be written about the evolution of Mercedes in response to the US market, from the 70s to the present, as they’ve recalculated designs according to customer tastes, changing technology, and (perhaps most dramatically) the rise of Lexus in the 90s.

    For all the drawbacks of the long throws, the engine noise from gearing ratios at high speed, and so forth–about which you’re spot-on–the manual in my 113 is so much fun to drive, and the exhaust note is wonderful (the sound of engineering, not “sound engineers” fiddling with the muffler or (laughably, to me) electronic tweaks to the stereo system, as in some new sports cars. The 113 as a whole can be a money-pit far beyond the 107, given the complexity of welded body work around the grill, hood, and fenders (none bolted on, as with 107’s); aluminum hood, trunk lid, doors, and use of metal instead of plastic in so many places (grill screen, dash, door sills, and on and on); complex, difficult-to-fit wood and other trim on the dash; literally countless grease fittings (and I do mean “literally” in the dictionary sense; even experts on SL forums seem to discover new ones); and antiquated rust-proofing on a body that seems designed to collect water rather than drain it in certain spots. The mechanical fuel injection needs adjustment beyond the skills of all but specialists, including MB dealers, and front-end body work is both expensive and, unless very well executed, will give itself away immediately in panel gaps around that lovely hood design. A 107 is a much saner and cheaper collector choice. But with a fairly well-sorted solid “driver,” by no means fully restored, I’ve never regretted getting my 113, which feels like a machine, not an appliance, yet is utterly easy to drive and rides better than many cars designed decades later. And the shape and proportions are to my eye almost perfect; next to it, the far-more-modern 107 sacrifices character for sleekness. In Dallas, I get happy waves from people who would never notice a 107 (which are all over the place) or a late-model SL that cost 5x what mine did to buy.

    Apologies for self-indulgent response. And thanks again for your work!

    1. Thanks, Rick! I think you’re right about the lights and have amended the caption. I was so distracted dealing with the paste-up (typing HTML img tags by hand — don’t ask) that I missed that.

      I would be very curious to know how many European W113s of each generation had automatic. Based on the comparative U.S. and rest-of-world production figures and the various estimates I’ve seen for the percentage of cars with automatic, it can’t have only been American buyers opting for it. Still, the fact that the U.S. R107 was offered only with automatic is noteworthy.

      For better or worse, the R107 is still too ubiquitous to really stand out. In this part of Los Angeles, it’s hard to go outside without seeing one and the longevity of the design means that it registers as an older car rather than an Old Car. (The C107 is considerably less common.)

      On the fuel injection system, I suppose it’s only fair to point out that most mechanical injection systems of that time were similarly intolerant of shade-tree mechanics. On Triumph’s 2.5 PI engine, for instance, the factory service manual included stern warnings not to even try adjusting or resetting the metering unit’s diaphragm springs, which required very fine tolerances.

      1. One would assume that since the R107 was offered only with automatic in the U.S., a majority of American W113 owners had ordered automatic. But there’s another wrinkle, which Road & Track mentioned in their first road test of the R107. Smog-certifying both manual and automatic R107’s for the U.S. would have been that much more expensive. Road & Track gave a figure (which I no longer remember) for the percentage of W113’s sold with automatic in the U.S. and said Daimler-Benz “had to go with the majority.”

        As an indication of one demographic to which the W113 appealed, I read an article around the time the BMW 325 Cabriolet was introduced. The writer said that until the advent of the 325 Cabriolet, the W113 was really the only game in town for doctors’ wives.

        To my eye the boxy look is fine on M-B sedans but not on the R107. The W113 is so much more graceful.

        1. The separate emissions certification cost is a major reason why we no longer get a lot of cars with manual transmission even if they’re sold that way in other markets — or if we do, the manual actually costs more than the automatic. (That said, it’s interesting to note that some Japanese cars have been sold here with manual transmissions that weren’t offered in the home market.) In any case, the newer three-speed torque converter transmission was probably better suited to U.S. driving styles anyway, particularly with a V-8 engine.

          I have a feeling the R107 was intended to look more “masculine.” I don’t recall offhand if the designers specifically said that (although they were certainly conscious that it was bigger and bulkier than the W113), but it would make sense from the results. I don’t know how the demographics of the R107 differed from those of the W113 overall, but at least in L.A., it seems the R107 had a fairly unisex appeal.

          I think perceptions of the R107 end up being skewed somewhat by the model’s longevity. Its lifespan overlapped several generations of Mercedes-Benz sedans, each of which became progressively sleeker while the roadster stayed (at least visually) the same. Not that the R107 isn’t objectively bulkier and less graceful than the W113, but having viewed it against cars of the late ’80s as well as the ’70s, the effect is exaggerated.

  4. This was a fascinating and quite comprehensive read. At the last Frankfurt Auto Show and more recently the Essen Techno Classica there were many W113s present. It is apparent their values are increasing, unlike the not particularly liked successor. A number of specialists here in Germany have taken to building cars that retain the 230-280SL styling but with modern Mercedes-Benz engines and transmissions. At an impressive price, of course!

  5. i learned to drive on my dad’s ’71 280sl. only negatives were the automatic, 4.08 rear end (felt bad taking her on the interstate), heavy a/c that was never used, and the points constantly frying up.

    love to do a resto-mod if the car would still sound the same. amazing exhaust note. perfect car for going to the golf course.

  6. Thank you for this article. As I’ve only just discovered this website, I am very impressed with the thoroughness and depth that make this article a true gem. Very inspiring.

  7. My grandmother bought a ’72 250C brand new, she kept it for 25 years, and I drove it a lot over that time. The comments on the Mercedes automatic transmission are so spot-on. If you drove it with just the right amount of partial throttle it shifted almost smoothly, anything else and it was jerking and slamming gears. Boy, I miss that car.

  8. Did any of the early 1964 230 SL come with dual carbs instead of Bosch fuel injection.

    1. Not from the factory, but since there were dual-carburetor versions of the 220 and 250 engines in the sedans, it seems entirely possible that someone might have done a swap for some reason.

  9. Owner of 1970 250C …..motor swapped on 76′ to a 280 S/A…..yes yes stamped on the head is S/A ….definitely not a 8 ….block says 130 923 12 001641 …does anyone know this model ? Closest I could come was a 280S a/c or the 280 S/8

  10. The Triumph Stag was aimed at more or less the same market segment as the W113 and R107. Unfortunately for the Stag, it was developed and introduced at a time of extreme dysfunction at British Leyland. It quickly acquired (and never really lost) a reputation for poor build quality and engine problems.

  11. Thanks for that fine article. I recently purchased a 1963 MB 230SL
    standard transmission. The car seems to be treated poorly at sometime during it’s past. The steering wheel cracked, the top of the ashtray is missing, but it is a fun car to drive, I am slowly bringing it back to good form. BTW, any idea where I can get a top to the ashtray? I fear that I might have to get it fabricated.

    1. I’m afraid I can’t help with parts or repairs, sorry!

  12. The Stag was a later car than the W113, and was an occasional 4 seater. Its main competitor , on the UK market a least , was the Reliant Scimitar GTC

    1. All true. On the other hand, the W113 was one of the key inspirations for the Stag (whose development was quite protracted) and Triumph explicitly hoped to make the Stag that kind of car. Obviously, the Mercedes was a lot more expensive (and the R107 350SL was even more so), and Triumph didn’t have that kind of cachet, but that’s the sort of buyer they wanted to court.

      Of course, it didn’t turn out that way, but massive disparities between intention and outcome are a central theme of the Stag story…!

  13. Rather intrigued by the 115-134 hp 2.2-litre output of the M127 engine in the Mercedes-Benz W127 prototype, both it not being produced with neither it or the Mercedes-Benz W121 featuring a coupe bodystyle were missed opportunities.

    Quite perplexed by the outputs of the M180 6-cylinder engine as find it difficult seeing capable of putting out 110 hp whereas the M127 was comfortably able to exceed those figures, also interested to know the M180 family’s relation to the larger M186 family.

    1. The issue was pretty plainly torque, and in particular the shape of the torque curve. Torque output with normally aspirated engines is directly related to displacement. Many of the changes that will provide more horsepower from a given displacement either won’t produce a commensurate increase in torque. Some will actually hurt torque output or at least alter the torque curve in undesirable ways. The M127’s torque peak was 4,500 rpm, which was quite high for the time and forced some awkward compromises in gearing to compensate. In the heavier sedans and coupes, that would have been even worse.

      It’s easy to lose sight of that issue when one becomes accustomed to modern engines, which are vastly more flexible. With modern engines, especially with forced induction, the torque peak doesn’t tell you much about the shape of the curve, whereas with early sixties technology, a torque peak above 4,000 rpm was likely to mean a very peaky, high-strung engine.

      1. Can understand as way variations on the M180 were still used to some extent instead of the M127, just brings up the question of whether even further could have been extracted from the M180.

        Like the idea of the Mercedes 190SL W121 receiving an 110 hp M180 or 115-134 hp M127 in W127 prototype form as a German equivalent to the Big Healey, which also switched from 4-cylinder to 6-cylinder engines.

        Despite the potential compromises in refinement and tractability, is it known how much more power was capable of being extracted from the 105 hp 1.9-2.0 M121 4-cylinder engine or what it would have likely entailed?

        1. I don’t have any details regarding what Nallinger tried in getting more power from the M121, but in that era, the steps involved in getting more power out of a given engine of given duration were generally straightforward: bigger ports, bigger valves, greater valve lift, longer duration, more carburetion. Not all of those are necessarily practical; for example, existing cylinder head design may impose limits on port size and shape, or oil system design may be inadequate for sustained high-rpm use. This makes your question more complicated than it might appear because some modifications may have required extensive and expensive design changes, such as new cylinder heads, for very modest improvements in power and significant cost to low-speed response.

          The Big Healey is potentially a misleading comparison because the switch from the big four to the six was initially a matter of production economy rather than a product planning decision; the initial 100-6 lost some ground in performance. (It’s also significant there that the 2.6-liter C-series six was actually about 21 cc smaller than the big four!)

          1. Read the M121 later M115 4-cylinder and the M180 family up to the M110 6-cylinder were related to each other (along with the dieselized 4/5-cylinder units), given the M121 and M180 engines shared history (and other related derivatives) it is strange the 6-cylinder was not capable of reaching 3-litres+.

            In theory an 1897cc/1988cc 4-cylinder M121/M115 of similar spec to the 134 hp 2196cc M123 or 168 hp 2778cc M130 have a potential output of 115-116 hp (1897cc) and 120-121 hp (1988cc) for an alternate 190SL W121. Meanwhile using the much later 182 hp 2749cc M110 Twin-Cam as a rough guide equates to a potential 1988cc 4-cylinder output of 132 hp.

            Brought up the Big Healey comparison because it immediately comes to mind even if the background for it differed from the W121 and W127 prototype.

          2. I can’t claim to be sufficiently familiar with the fine details of Mercedes engines to tell you how closely their four- and six-cylinder engines of this vintage relate to one another. However, comparing specific outputs the way you’re doing is potentially misleading. A six-cylinder engine has a number of intrinsic advantages, including in breathing, and if the engines are part of the same family, the six will also have greater displacement and thus more torque. Even for engines of identical displacement, the four will need significantly bigger valves to match the total valve area of the six, which the standard port design might not easily accommodate, and would need greater valve lift and longer duration to compensate, hurting low-end response.

            My suspicion — which again I’m not familiar enough with the engine development saga to confirm — is that porting ended up being a limiting factor for the M121. Small ports have advantages; they tend to give better low-end torque because you have greater intake velocity at low rpm, and they allow the head to be physically smaller. They obviously become a bottleneck when it comes to extracting more power, but if you have a closely related small-displacement six, that may not seem like a significant problem. However, if you want to get more power out of the four, the port design may leave you boxed in, wrestling with questions like whether it’s worth the cost to completely redesign the head for a gain of a few horsepower.

            As for the displacement, I don’t think that one should assume an engine not being expanded beyond a particular threshold meant that it wasn’t capable of being expanded that far. The 2.8-liter threshold was a pretty hard limit in terms of taxation in some markets, like France, and Mercedes-Benz wasn’t yet centering the U.S. market in their product planning decisions. They may well have said, “We’ve already got a 3-liter engine for the few applications that need it,” and left it at that.

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