BMW 8 Series 830i

Although sales were good in the first year on sale, the sharp reduction of the expensive 850i sales prompted BMW to develop an entry-level model. This was to use the 3-liter V8 with 218 PS (160 kW; 215 hp) from the 530i and 730i, known internally as the M60B30. Eighteen cars were produced, 13 of which had an automatic gearbox fitted. The model was dropped in favor of the 840Ci and all 18 development cars were dismantled.

BMW 8 Series 840Ci

The 840Ci exists with two different engine packages. The first used the 4 liter M60B40 engine with 286 PS (210 kW) and was produced from mid 1993 to late 1995. From mid-1995, production phased in the newer 4.4 liter M62B44 engine, which had better fuel economy and more torque, though power output remained unchanged.

The 840Ci was available with a 5-speed automatic transmission, though European cars were given the option of a 6-speed manual transmission. The only external features distinguishing the V8 model from the V12 models were the quad round exhausts, which were square in the V12 models. The 840Ci stayed in production until mid-1999.

BMW 8 Series 850i

This was the first model launched in 1991 with the 5 liter M70B50 V12 engine producing 300 PS (221 kW; 296 hp). It was available with either a 4-speed automatic or a 6-speed manual gearbox.

BMW 8 Series 850Ci

There is some confusion over why and when the 850i became the 850Ci. The change happened around the introduction of the 850CSi and it is believed that BMW decided to include the "C" in the model name to create more of a distinction between the 8 Series and BMW's saloons. The confusion starts when BMW installed the new M73B54 engine in the car. This was not an immediate changeover, and indeed both the M70 and M73-engined cars rolled off the production lines side-by-side for about nine months in 1994, both named 850Ci.

As the capacity of the M73 increased to 5.4 liters and the compression ratio went up, the power output rose to 326 PS (240 kW; 322 hp).

BMW 8 Series 850CSi

As a top-of-the-range sports tourer, the 850CSi took over from the prototype M8. The 850CSi used the same engine as the 850i, which was tuned so significantly that BMW assigned it a new engine code: S70B56. The modifications included a capacity increase to 5.6 liters and power increase to 380 PS (279 kW; 375 hp).

The 850CSi's modified suspension included stiffer springs and shock absorbers and reduced the car's ride height. The re-circulating ball steering ratio was dropped 15% over the stock E31 setup. The model also sported wider wheels, with the option of forged alloys. The front and rear bumpers were reshaped for improved aerodynamic performance. Four round stainless steel exhaust tips replaced the square tips found on other models. The 6-speed manual gearbox was the only transmission option.

Production ended in late 1996 because the S70 engine could not be modified to comply with new emission regulations without substantial re-engineering.

BMW 8 Series M8

Originally envisioned as a Ferrari competitor, only a single prototype BMW M8 was ever produced, equipped with a special 550 bhp (410 kW) version of the S70 engine, essentially a bored out version of the M70 with experimental multi-valve cylinder heads. A common misconception is that this engine powered the McLaren F1. However, when this was suggested to McLaren's designer Gordon Murray, the idea was rejected because the engine was too heavy and long for the McLaren F1. A completely new BMW engine was designed which has a closer resemblance to the later Euro S50B30 BMW M3 engine.

The project was eventually scrapped because BMW decided that there was no market for an M8. The only prototype ever produced (one that was reportedly not even road safe) was locked away by BMW in the company's Giftschrank (poison storage) and has reportedly been destroyed.

While the M8 was never produced, it is interesting to note that the 850CSi was also tuned by BMW's M division. Aside from sporting an M-tuned engine (as identified by the S suffix instead of the M prefix that a non-M tuned engine would wear), the car's VIN identifies the car as being built by BMW Motorsport (identified by the WBS prefix) instead of BMW AG (WBA prefix). This effectively identifies the 850CSi as essentially a detuned version of the M8.

BMW 8 Series Alpina B12

BMW tuner Alpina produced a special version of the 8 Series dubbed the B12. Two versions were produced, both taken from the standard production line. The B12 5.0 Coupe was based on the 850i, powered by the 5.0-liter M70 engine producing 350 bhp (260 kW), and available only with a 4-speed automatic gearbox. The larger B12 5.7 Coupe was based on the 850CSi, with the 5.7-liter S70 engine producing 416 bhp (310 kW; 422 PS) with a 6-speed manual gearbox.

BMW 8 Series Racing Dynamics K55 Sport Coupe

BMW tuner Racing Dynamics of Italy in 1991 produced a special version of the 8 Series dubbed the K55 Sport Coupe taken from the standard production line. The K55 5.5 Coupe was based on the 850i, powered by the 5.0-liter M70 that was stroked to 5.5 liters, new valves, camshafts lifters and intakes along with extrude honed heads. The one US version engine producing 475 bhp (354 kW; 482 PS) and the Euro version producing 401 bhp (299 kW). 40 K55s were produced for the Euro market and one in the US. In addition to engine modifications, The K55 offered a variety of body, suspensions, rear end options. References 02/1994 Euro Magazine Road & Track, Car and Driver.

However, there is no verification of 475 hp (354 kW) produced by this car by Racing Dynamics. The K55 produces 380 hp (280 kW) as listed in the 02/1994 Euro car magazine. Racing Dynamic's own website lists the K55 at 401 hp (299 kW).

The 475 hp (354 kW) was declared by Autothority (as listed in the said Road & Track article) who are no longer in business in their original capacity. The 475 hp (354 kW) claim was never verified.