Written by Tom Carter, E31 specialist.
Over the eleven years of E31 production in Europe, BMW fitted the 8 Series with five distinct engines — all sharing a family resemblance, yet each with a different character. Every E31, regardless of engine, was factory-limited electronically to 250 km/h (155 mph).
850i and 850Ci — 1989–1994 (Europe) / 1991–1994 (North America)
The original 850 carried the M70 5.0-litre V12, borrowed from the E32 750iL. In stock form it produced 296 bhp and 331 ft-lb of torque — impressive figures for the era, though the car's substantial weight prevented it from competing with purpose-built performance exotics.
With stock final-drive ratios of 3.64 on four-speed automatics and 2.65 on the six-speed manual, the 850i was clearly tuned for sustained high-speed cruising rather than hard acceleration. Some Japanese-market examples were fitted with a 3.91 differential, giving them noticeably livelier off-the-line response.
- Engine: M70 5.0L V12
- Output: 296 bhp / 331 ft-lb torque
- Final drive: 3.64 (auto) / 2.65 (6-speed manual)
- Total worldwide production: 20,072
850CSi — 1992–1996 (Europe) / 1993–1995 (United States)
The CSi was, in practice, what the 850 should have been from the start. Never officially badged as an M car, it was nonetheless conceived as the performance variant of the range. It used the S70 5.6-litre V12 — derived from the M70 but substantially reworked — producing 376 bhp and 405 ft-lb of torque.
Kerb weight stayed roughly the same as the standard car, but the CSi paired its extra power and torque with meaningfully better chassis hardware: stiffer factory sway bars, lowering springs, and a 2.93 final drive with a 25% limited-slip differential. Some European examples also received active rear-wheel steering (AHK). Every CSi left the factory with a six-speed manual transmission — there was no automatic option.
Of the 1,510 built worldwide, 225 were shipped to the United States. The CSi was never imported into Canada and remained prohibited for import for reasons that were never clearly articulated. Collectors looking for European or Japanese-market BMW alternatives can browse BMW listings on JDMBuySell, where grey-market and JDM-spec imports occasionally surface.
- Engine: S70 5.6L V12
- Output: 376 bhp / 405 ft-lb torque
- Final drive: 2.93 with 25% limited-slip differential
- Transmission: 6-speed manual (only)
- Total worldwide production: 1,510
850Ci (Late) — 1994–1999 (Europe) / 1994–1997 (North America)
The later Ci received the revised M73 5.4-litre V12. Though the M73 was based on the M70 architecture, very few parts were interchangeable between the two. Output climbed to 332 bhp and 361 ft-lb of torque, and the engine was mated exclusively to BMW's five-speed Steptronic transmission with a 2.81 final drive.
- Engine: M73 5.4L V12
- Output: 332 bhp / 361 ft-lb torque
- Final drive: 2.81
- Transmission: 5-speed Steptronic
- Total worldwide production: 1,218
840i and 840Ci — 1992–1999 (Europe) / 1994–1997 (North America)
The eight-cylinder cars used two successive V8 engines over their production run.
M60 4.0-litre V8 (early cars)
Early 840s came with the M60 4.0-litre four-valve V8, producing 282 bhp and 295 ft-lb of torque with a 2.93 final drive. Because the 840 was slightly lighter than the V12 cars, real-world performance was closer than the engine figures alone suggest.
M62 4.4-litre V8 (later cars)
Later production switched to the M62 4.4-litre four-valve V8 — based on the M60 — with 286 bhp and 309 ft-lb of torque and a 2.81 final drive. The torque gain over the M60 was the meaningful difference in everyday driving.
- M60 output: 282 bhp / 295 ft-lb torque — final drive 2.93
- M62 output: 286 bhp / 309 ft-lb torque — final drive 2.81
- M60 production: 4,728
- M62 production: 3,075
Total E31 Production
Total worldwide E31 production across all variants came to 30,603 units. This figure excludes 18 BMW 830 prototypes that were never publicly released.
For more on the local E31 community, the BC 8s Special Interest Group maintained a dedicated resource at www.wuffer.net.