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.
In its 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 to what they might 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 seeming a little out of place.
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. Based on the contemporary Mercedes 180 “Ponton” sedan, the 190SL 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.
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.
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 their 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.