Development of the 8 Series began in July 1981, with the design phase reaching completion in 1986, although the launch was delayed due to still-strong 6 Series sales.[8] The 8 Series debuted at the Frankfurt Motor Show(IAA) in early September 1989. The 8 Series was designed to move beyond the market of the original 6 Series. The 8 Series had substantially improved performance, as well as a far higher purchase price.

Over 1.5 billion Deutsche Marks were spent on total development ($1.13 billion USD or €990 million in 2025).[9] BMW used CAD tools, still unusual at the time, to design the car's all-new body. Combined with wind tunnel testing, the resulting car had a drag coefficient of Cd=0.29, a major improvement from the previous BMW M6/635CSi's 0.39.[10]

The 8 Series offered the first V12 engine mated to a 6-speed manual transmission on a road car. It was one of the first vehicles to be fitted with an electronic drive-by-wire throttle. The 8 Series was one of BMW's first cars, together with the Z1, to use a multi-link rear axle.[8][10]

CAD modelling allowed the 8 Series unibody to be 3 kg (6.6 lb) lighter than that of the preceding 6 Series (E24). However the production 8 Series was significantly heavier when completed due to the large engine and added luxury items—a source of criticism from those who wanted BMW to concentrate on the driving experience. Some of the car's weight may have been due to its pillar-less "hardtop" body style which lacked a "B" pillar.