Status-Seeking Missiles: The BMW E24 6-Series Coupes

A FEDERAL CASE

The 6-Series didn’t come to America until 1977. When it finally did appear, American buyers had the dubious pleasure of paying far more money for noticeably inferior performance. The initial federalized 630CSi model was heavier than its European counterparts, thanks to bigger bumpers that added nearly 5 inches (12 cm) to its overall length. The only engine choice at launch was a fuel-injected version of the 2,985 cc (182 cu. in.) engine making 176 horsepower SAE (131 kW). Despite its power-to-weight deficiencies, the U.S. 630CSi carried a starting price tag of about $23,500 (the equivalent of around $85,000 in 2010), nearly 50% more than a German-market 630CS. Admittedly, the 630CSi was around $4,000 cheaper than a Mercedes 450SLC, but neither was priced within the reach of mere mortals.

American critics liked the 630CSi’s looks and handling, but its towering price cooled their ardor. Most preferred the 5-Series sedan, which performed just as well, was far more practical, and cost a good deal less.

BMW, apparently stung by the criticism, hastened to introduce a federalized 633CSi in 1978, dropping the 2,985 cc (182 cu. in.) engine in favor of a smog-controlled version of the 3,210 cc (196 cu. in.) M30 six also used in the new 733i sedan. The U.S. 633CSi had only fractionally more power than the 630CSi — 177 hp SAE (132 kW) — but stronger mid-range torque gave it better real-world performance than the earlier car.

Still, many buyers had evidently reached the same conclusions as the magazine testers and U.S. 6-Series sales were modest. BMW’s American sales grew impressively throughout the late seventies and early eighties, but the big coupes represented a very small fraction of that business. Throughout the E24’s lifespan, the U.S. market accounted for less than 30% of total sales.

THE 635CSi

The European BMW 633CSi was a close match for a 450SLC in overall performance, but in 1978, Mercedes upped the ante with the limited-production 450SLC 5.0 (subsequently renamed 500SLC), which featured a new all-aluminum 4,973 cc (305 cu. in.) V8 with 240 PS DIN (176 kW). Since the new coupe was both lighter and more powerful than the previous 450SLC, the 450SLC 5.0 was decisively quicker than both its predecessor and the 635.

1980 BMW 635CSi front 3q (© 2005 Jim Gunnee; used with permission
In addition to its larger M90 engine, the BMW 635CSi had stiffer anti-roll bars, wider BBS wheels (albeit with the same 195/70VR-14 tires as lesser models), and front and rear spoilers that were claimed to substantially reduce aerodynamic lift. Anti-lock brakes became optional in 1979 and Bosch Digital Motor Electronics — controlling ignition timing as well as fuel injection — was added in 1980. (Photo: 1981 BMW 635csi – Car No8″ © 2005 Jim Gunnee; used with permission)

Given Von Kuenheim’s Mercedes envy, such a challenge could not go unanswered. BMW’s response appeared in July 1978 as the 635CSi, powered by a new six-cylinder engine called the M90. Similar to the M88 engine developed for BMW’s short-lived M1 supercar, the M90 was bored and stroked to 3,453 cc (211 cu. in.), although it retained a SOHC head and two valves per cylinder. The combination was sufficient for an output of 218 PS DIN (160 kW), a healthy improvement over the 633CSi. Linked to a new Getrag five-speed gearbox, the M90 engine gave the big coupe’s performance a shot in the arm: 0-60 mph (0-97 km/h) was now possible in less than eight seconds while top speed climbed to nearly 140 mph (224 km/h), outstanding for the time. The following year, the 635CSi also got optional Bosch antilock brakes, again to maintain parity with Mercedes. (ABS was not available on U.S. 6ers until 1985.)

The 635CSi proved very popular, particularly in Germany, where it cost less than 10% more than the 633CSi. In its first year, the big-engine model accounted for nearly a quarter of production, rising to more than 50% in its second year. Starting in mid-1979, there was also a new base model, the fuel-injected 628CSi, replacing the carbureted 630CS. However, buyers who could afford a 6-Series were apparently unmoved by the smaller engine’s modest cost savings and slightly better fuel economy; BMW sold only 5,950 628CSi models between 1979 and 1987.

1981 BMW 635CSi rear 3q © 2005 Jim Gunnee; used with permission
The rear bumpers of European E24s were redesigned early in the 1981 model year, wrapping around the rear fenders for better parking protection. This U.K.-market 1981 still has the old bumpers, but it has the newer, slimmer rear spoiler, also new for 1981. Note the “Parsol” bronze window tint, standard on European E24s. At launch, BMW admitted that the bronze tint was selected mainly for aesthetic reasons and was somewhat less effective than the customary green tint. Untinted and green-tinted windows were no-cost options; the latter were normally included with air conditioning, which was optional on European 6-Series. (Photo: “1981 BMW 635csi – Car No8” © 2005 Jim Gunnee; used with permission)

THE 6-SERIES IN COMPETITION

BMW racing teams were slow to adopt the E24, since the old 3.0 CSL remained competitive in European Touring Car (ETC) competition as late as 1979. Group 2 versions of the 6-Series made their first foray onto the racetrack in 1980. In 1981, Helmutt Kelleners and Umberto Grano used 360 hp (264 KW) racing versions of the 635CSi, prepared by Ruedi Eggenberger, to tie for the ETC driver’s championship.

1975 (?) BMW 3.0 CSL 'Batmobile' © 2018 Andrew Buc; used with permission

The BMW 3.0 CSL “Batmobile,” so named because its assortment of spoilers was outlandish for its day, was the raciest of the E9 series and remained a surprisingly successful competition car into the late seventies. (Photo © 2018 Andrew Buc; used with permission)

In 1982, the Fédération Internationale de l’Automobile (FIA) switched the ETC from Group 2 to Group A rules, which greatly restricted the number of allowable modifications. BMW Motorsport and Ruedi Eggenberger decided to switch to the smaller 528i sedan, which Umberto Grano used to win the 1982 ETC driver’s cup. The following year, however, Eggenberger switched back to the 635CSi, which Dieter Quester used to win the 1983 driver’s cup. The 6-Series didn’t fare as well in 1984 and 1985, but Axel Feder won the 24 Hours Nürburgring both years, driving a Schnitzer-built 635CSi. Finally, in 1986, Robert Ravaglia drove another 635CSi to the type’s third and final ETC championship.

The 6-Series also fared well in Australian competition. Driver Jim Richards won both the 1985 Australian Touring Car Championship and the 1985 AMSCAR series in a 635CSi and became Australian Endurance Champion in both 1985 and 1986.

While the racing 6-Series never quite equaled the record of the 3.0 CSL, its competition pedigree was nonetheless impressive. It also cemented the 6-Series’ role as BMW’s image leader, a role it arguably fulfilled better than the company’s intended flagship, the decidedly Mercedes-like 7-Series sedan.

1981 BMW 635CSi M90 engine © 2018 Andrew Buc; used with permission
The 3,453 cc (211 cu. in.) M90 engine of the early 635CSi was essentially a SOHC 12-valve version of the M88 engine in the BMW M1, needing conjoined cylinder bores to accommodate its 93.4 mm (3.67-inch) bore dimensions. This 1981 car has Bosch Digital Motor Electronics (DME), added to the big engine the previous year. In 1982, the M90 was replaced by the M30B34, which had a narrower 92 mm (3.62-inch) bore and the longer 86 mm (3.38-inch) stroke of the 3,210 cc (196 cu. in.) engine from the 633CSi, reducing displacement to 3,430 cc (209 cu. in.). The M30B34 was less racy than the M90, but was more reliable and somewhat cheaper to build. (Photo © 2018 Andrew Buc; used with permission)

15 Comments

Add a Comment
  1. Thank you for the well-written article on the BMW 6-series. As an owner and fan of this model, I have a few corrections to make to the text as presented:

    1. The 1977 Mercedes 450SLC as pictured is really just a 450SL with removeable hardtop in place. The SLC had a slightly longer roofline with a character line down the side of the pillar to differentiate itself from the roadster.

    2. Another picture caption states that headlamp wipers were standard fit on U.S. 6-series models. This is untrue. The U.S. 6-series never offered headlamp wipers even as an option, these were only available on Euro-spec models. It should also be noted these are very troublesome and are rarely found in working condition.

    3.Another photo caption mentions the “power seat controls” to the left of the on board computer. These are actually switches for the heated seats option, with 2 levels of intensity available. Power seat controls on cars so equipped are located near the parking brake.

    4. The next photo caption mentions Michelin “TDX” metric tires that many 6-series were equipped with. The correct term is Michelin “TRX” tires. These tires were perhaps worthy of more discussion as they have high prices and very limited availability today due to their odd size and outdated nature. This is why most 6-series models seen today feature wheels and tires from other models of BMW’s with more standard sizing.

    5. Another portion of text says a drivers side airbag became available in 1985. When referring to U.S. cars, this is not the case. U.S. cars were only fitted with the second generation BMW airbag wheel and not until the 1988 model year.

    These corrections may be nitpicky, but they are important in understanding the story of the 6-series and especially how trim differed wildly by sales market.

    1. Thanks for the corrections! The TRX/TDX glitch was a typo (now fixed), and I’ve amended the text to reflect these notes.

      The 450SL was misidentified by the dealer selling it — it’s entirely possible they weren’t clear on the distinction between the SL with hardtop and the SLC, either.

  2. Very well-researched and written article. As a 6er owner and enthusiast, I appreciate the tribute.

    You’ve got a “subscriber!” Keep up the excellent work.

    Cheers,
    Matt

  3. Great article on one of my favorite BMWs. I do have one small correction: the MN12-platform Thunderbird that looks so much like a scaled up 6-series began production as a 1989 model.

    1. Ahah, you are quite right. I’ve made that correction in the text.

  4. The early model 6ers can also be identified by their steel side view mirrors, plastic folding mirrors came along with the E28 based models in 1983 if I remember correctly.

  5. thanks for the article (and the further articles e.g. about the Porsche 928)

  6. These cars are actually good. They are not ostentatious like the 21st century BMW 6 series. Love these!

  7. Nice article it’s still fun to drive and maybe even better as mine is no status symbol just fun
    If you wanted the best and unique you got it

  8. My first BMW was a gift in March 2015. 1984 633CSi automatic transmission. A month later, I rescued a 1983 from the junkyard. My 1967 Mercedes 250s is nice, but my 6 is a daily driver. I drove Fords my entire life and I’m now restoring Euro cars at my own pace. The engineering and design are amazing.

  9. As a young kid growing up in the StLouis Area, My dad had (3)bimmer 1988 m5, 1982 e24, 1987 325i e30, along with 3 son. After passing he actually gave the cars to us. Of course i was the middle son i got the e24. The was recked being seting in brother garage for 6 years or more, and the e30 my brother teenage is driving that one. To my suprise he have put over 3,500k into the it. New tires,piant job, muffler plus cat and header.He put some blisten shocks on it, did i mention the engine work, it was rebuilt.

    Now, for the e24, im restoring it with the OEM. I started last year around this time, i’m still have a long way to go. my problem is, i can’t find a dashboard for my car. living down here the south, in the terrible sun, totally desroyed the dash. But now i have a garage where i store the car daily. I have looked everywhere, UK, Canada, USA, and even in Germany, i even looked in the junk/salavage yards.

    What do you guys think, you can’t buy a new one becuase BMW stop making them, and if i do find one it’s in the junk yard (it’s just that… JUNK) worse shape than the one i have.

    byrdwl2003@yahoo.com/willie.byrd@dayzim.com

    1. try a dash topper instead which slips directly over your old one.
      There are many available for your E24.

    2. Why don’t you check with the auto upholstery shops? Some of them can recover them for you. It would probably be better then all the used ones.

  10. For BMW to nearly double their sales from 1966 to 1969 was pretty impressive. But I assume that a lot of the production capacity came from their acquisition of Glas.

    1. Capacity, certainly. I confess I don’t have a clear idea of what their production capacity was before that acquisition, although it appears they were not using all of whatever it was.

Leave a Reply

Your email address will not be published. Required fields are marked *

Comments may be moderated. Commenting signifies your acceptance of our Comment Policy — please read it first! You must be at least 18 to comment. PLEASE DON'T POST COPYRIGHTED CONTENT YOU AREN'T AUTHORIZED TO USE!