BMW 8 Series (E31): BMW’s V12 grand tourer

The 8 Series of 1990 was not a direct replacement for the 6 Series but a new class altogether, with a much higher price and much more performance. It was a pillar-less coupé powered by a V8 or a V12, developed at great expense with computer-aided design and shaped in a wind tunnel. Sales were hit by the recession of the early 1990s, and a planned M8 was never built.

BMW 8 Series (E31) at a glance

Based on one source, the English Wikipedia article on the E31; the German article was not available.

History of the BMW 8 Series (E31)

Development

Work on the 8 Series began in July 1981 and the design phase was complete by 1986, but the launch was postponed while the 6 Series was still selling well. The car debuted at the Frankfurt Motor Show in September 1989. Total development cost more than 1.5 billion Deutsche Marks. BMW used computer-aided design, still unusual at the time, for the new body, and combined it with wind tunnel work to reach a drag coefficient of 0.29, well below the 0.39 of the M6 and 635CSi. The unibody was 3 kg lighter than the E24’s, although the finished car was heavy because of the large engines and the luxury equipment; the pillar-less roof contributed as well. With the Z1, the 8 Series was among the first BMWs with a multi-link rear axle, and the 850i was one of the first cars with an electronic drive-by-wire throttle.

The range

The 850i of 1990 used the 5.0-litre M70 V12 with 220 kW (300 PS), offered with a four-speed automatic or a six-speed manual; it was the first production road car to combine a V12 with a six-speed manual. It was renamed 850Ci in autumn 1993, and from October 1994 the 5.4-litre M73 V12 raised output to 240 kW (326 PS). The 840Ci became the entry model with the 4.0-litre M60B40 V8 of 210 kW (286 PS) from mid-1993, replaced by the 4.4-litre M62B44 from mid-1995 with better economy and more torque but the same power; European buyers could order a six-speed manual. Quad round exhaust tips distinguished the V8 cars from the square tips of the V12s, and the 840Ci stayed in production until May 1999.

850CSi and sales

The 850CSi took the place of the abandoned M8. Its engine was tuned so far that BMW gave it a new code, S70B56: 5,576 cc, 280 kW (381 PS) at 5,300 rpm and 550 N·m at 4,000 rpm, with a six-speed manual as the only gearbox. It had stiffer springs and dampers, a lower ride height, a steering ratio 15% quicker, reshaped bumpers and staggered wheels; European cars also received four-wheel steering, ventilated brakes with floating front discs and oil coolers for the differential and engine. Production ended in late 1996 because the engine could not meet new emission rules without extensive re-engineering. Sales of the range suffered from the early-1990s recession, the Gulf War and energy price rises, the M8 was cancelled in 1991, and BMW left the North American market in 1997.

Design and features

• Two engines: the M60 and M62 V8s and the M70, M73 and S70 V12s.
• Aerodynamic body: a drag coefficient of 0.29 from CAD design and wind tunnel testing.
• Pillar-less hardtop: no B-pillar, which added weight but gave the car its distinctive profile.
• 850CSi chassis: lower and stiffer, with quicker steering and four-wheel steering in Europe.
• Electronic throttle: drive-by-wire from the start, unusual for 1990.

BMW 8 Series (E31) versions

• 850i (1990–1993): 5.0-litre M70 V12 with a four-speed automatic or six-speed manual.
• 850Ci (1993–1999): the M70 car renamed, then the 5.4-litre M73 from October 1994.
• 840Ci (1993–1999): V8 entry model, M60 then M62, 7,803 cars in total.
• 850CSi (1992–1996): S70 engine, 381 PS, six-speed manual only, 1,510 built.
• 830i prototypes: 18 cars built before the V8 entry model was chosen instead.

The 8 Series was the grand tourer above the 7 Series (E38), whose 750i later shared a V12 with the 850Ci. Its rival in the range was the M5, and more cars are in the BMW collection.

Sources

• BMW 8 Series (E31), English Wikipedia: development, models, production figures, 850CSi