BMW M8 history: from the secret E31 prototype to the F92 coupé
The BMW M8 waited almost 30 years to reach production. The story of the secret E31 prototype, the 850CSi and the modern M8 coupé, convertible and Gran Coupé.
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The BMW M8 has one of the most unusual stories in the history of BMW M. In the early 1990s, BMW built a secret high-performance version of the E31 8 Series, but it never reached production. It took almost three decades before a production BMW M8 finally arrived.
In this article we follow the story of the BMW M8: the hidden E31 prototype and its V12 engine, the 850CSi that brought some of its spirit to customers, the modern F91, F92 and F93 models and the M8 racing cars.
The E31 8 Series: the starting point
The E31 8 Series was introduced in 1989 as BMW's new flagship coupé. It was a technological showcase with a V12 engine, a sleek wedge shape, pop-up headlights and pillarless side windows. Our dedicated article on the E31 8 Series tells its full story.
With such a dramatic car in the range, it was natural that BMW Motorsport would think about a high-performance version. An M version of the 8 Series could have competed with the fastest grand tourers of the time.
At the beginning of the 1990s, BMW Motorsport GmbH began work on such a car. The project was kept quiet, and for many years the public knew very little about it. The car later became known simply as the E31 M8 prototype.
The prototype was meant to show what the 8 Series could become with full M treatment: more power, less weight and a more aggressive appearance. As it turned out, it became one of the most famous BMW cars that was never sold.
The secret E31 M8 prototype
The E31 M8 prototype used a high-performance V12 engine developed by BMW Motorsport, with a capacity of around six litres. Commonly cited figures suggest an output of around 550 hp, although the exact specification of the prototype is not fully documented.
The car reportedly had a lighter body, with lightweight materials and simplified equipment, as well as special wheels and a more aggressive appearance than the regular 8 Series.
The project was stopped before production. Reasons that are often mentioned include the economic situation of the early 1990s, the high cost of producing such a car and doubts about the size of the market.
For many years, the car was kept out of public view. BMW finally presented the E31 M8 prototype to the public in 2010, which gave fans a first proper look at the car they had only heard rumours about. It has since appeared at events and remains a fascinating part of BMW Group Classic's collection.
The 850CSi and the McLaren F1 connection
Although the M8 did not reach production, some of its ideas found their way to customers. The BMW 850CSi, introduced in 1992, was the most powerful production version of the E31.
It used a 5.6-litre V12, the S70, developed with the involvement of BMW Motorsport. It produced around 380 hp and came with a manual gearbox, firmer suspension and other changes. The 850CSi is often seen as the closest thing to a production M8 of that era.
The V12 engine story continued in an even more spectacular way. BMW Motorsport developed the S70/2 V12 engine for the McLaren F1 road car, launched in 1992. With a capacity of about 6.1 litres and over 600 hp, it powered one of the most famous supercars of all time and later won the Le Mans 24 Hours in 1995 in the McLaren F1 GTR.
The connection between the E31 M8 prototype and the McLaren F1 engine is often discussed by enthusiasts, as both came from the same period of V12 development at BMW Motorsport.
The return of the BMW M8 name
After the E31 ended production in 1999, BMW did not build an 8 Series for almost two decades. The name returned in 2018 with the new G15 8 Series Coupé, followed by the G14 Convertible and the G16 Gran Coupé.
This time, an M version was part of the plan from the beginning. BMW showed the M8 Gran Coupé concept in 2018, giving a preview of the design. In 2019, the production BMW M8 arrived in three body styles: the F92 Coupé, the F91 Convertible and the F93 Gran Coupé.
This was the first time a BMW M8 was available for customers. Almost 30 years after the E31 prototype, the name finally appeared on a production car.
The new M8 was positioned as a high-performance luxury grand tourer, competing with some of the fastest cars in its class. It shared many components with the F90 M5, including its engine and all-wheel-drive system, but with a more exclusive design and character.
F91, F92 and F93: the modern M8
The modern BMW M8 uses the S63 4.4-litre twin-turbo V8 engine. In the standard M8 it produced 600 hp, and the M8 Competition produced 625 hp. Power goes through an eight-speed M Steptronic transmission to the M xDrive all-wheel-drive system.
M xDrive has a rear-axle bias and offers several modes, including a 2WD mode that sends all power to the rear wheels. An Active M Differential distributes torque between the rear wheels.
The M8 also introduced new control features for BMW M. The M Mode button allowed drivers to choose between Road, Sport and, in Competition models, Track settings for the driver assistance and display systems. The brake system offered selectable pedal feel.
The three body styles each had their own character. The Coupé was the sportiest, the Convertible offered open-air driving and the four-door Gran Coupé added practicality. Later updates refreshed the design and equipment. As with all modern BMW M models, exact specifications varied by market.
The BMW M8 in motorsport
The M8 name also returned to the racetrack. BMW developed the M8 GTE, a racing car for endurance racing in categories such as the American IMSA series and the FIA World Endurance Championship.
The M8 GTE made its competitive debut in 2018. One of its biggest successes came at the Daytona 24 Hours, where BMW won its GTLM class in 2019 and again in 2020. These results gave the M8 name a strong racing reputation.
A customer racing version, the BMW M8 GT3, was not built. Instead, BMW chose the M6 GT3 and later the M4 GT3 for customer GT3 racing.
The M8 GTE programme ended as BMW changed its motorsport strategy and moved towards new categories, including the hypercar-style prototypes of the M Hybrid V8.
For fans, the M8 GTE remains an important part of the M8 story. It showed that the name could stand for racing performance, just as the original E31 prototype was intended to do.
Why the BMW M8 story matters
The BMW M8 story shows how ideas can survive for decades inside a company. The E31 prototype was never sold, but it influenced the 850CSi, it became part of BMW's V12 development and it lived on as a legend among fans.
When the modern M8 finally arrived, it carried that legacy with it. It became the flagship of the BMW M range, showing the best of what the company could build at the time.
For collectors, the 850CSi is a special classic with a clear link to the M8 project. The modern M8 Competition models, in good condition and with documented history, may also become sought-after in the future, as they are among the last BMW M grand tourers with a purely combustion-engined V8.
For enthusiasts, the M8 is a reminder that some of the most interesting cars are those that took the longest to arrive. The road from a secret prototype to a production car took almost thirty years.
BMW M8 timeline
| Item | Details |
|---|---|
| E31 M8 prototype | Early 1990s, V12 of about 6 litres, not produced |
| Presented to the public | 2010 |
| 850CSi | 1992-1996, 5.6 S70 V12, about 380 hp |
| M8 production start | 2019 (F91, F92, F93) |
| Engine | 4.4 S63 twin-turbo V8 |
| Power | M8: 600 hp / M8 Competition: 625 hp |
| Drive | M xDrive with 2WD mode |
| Racing | M8 GTE, Daytona class wins 2019 and 2020 |
Frequently asked questions
Did BMW build an M8 in the 1990s?
BMW Motorsport built an E31 M8 prototype in the early 1990s, but it never went into production. It was shown to the public in 2010.
What engine was in the E31 M8 prototype?
A high-performance V12 of around six litres developed by BMW Motorsport. Its exact specification is not fully documented.
Is the 850CSi an M car?
It was not badged as an M car, but it was developed with BMW Motorsport and used the S70 V12. Many see it as the closest production car to an E31 M8.
How much power does the modern BMW M8 have?
The M8 has 600 hp and the M8 Competition 625 hp from a 4.4-litre twin-turbo V8.
What body styles does the M8 come in?
Three: the F92 Coupé, the F91 Convertible and the F93 Gran Coupé.
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