25 years of BMW 12-cylinder engines

BMW’s second-generation 7 Series, unveiled in 1986, featured two new top-of-the-range sedans whose formidable six-cylinder in-line engines generated universal enthusiasm in the motoring media. Nevertheless, it was an open secret that an even bigger star was waiting in the wings: the first German 12-cylinder luxury model in half a century. Expectations were running high, fuelled by BMW’s release of various advance details of the new model’s technical specifications. In September 1986, one news magazine informed its readers: “BMW will be opting for an aero engine-style design. That means most engine systems on the 12-cylinder 7 Series model, which is due for market release in June 1987, will be duplicated. There will even be two lambda sensors. And even if half the engine capacity failed, for some reason, speeds of over 200 km/h would be possible even on just six cylinders.” Last but not least, BMW’s development chief at the time was quoted as saying: “if the engineers wanted to go for nothing but the best of everything, we didn’t try to stop them.” The rumour mill was rife with speculation about the future top-of-the-line engine’s capabilities. One story doing the rounds claimed that: “BMW is doing everything it can to promote a sense of exclusiveness and cachet. They even want the licensing authorities to allow them to state the performance not in figures but in words – to the effect that the engine is appropriate in power and performance for the requirements of the vehicle.” In February 1987, BMW finally put an end to the speculation and released the technical specifications of the 12-cylinder engine in the new BMW 750i, ahead of its world debut at the Geneva Motor Show the following month. The new engine, which had been designed completely from scratch, would develop 300 horsepower from a displacement of five litres. Its refinement, low noise levels and excellent balance between performance and fuel consumption set new benchmarks in engine design. These objectives were achieved by using state-of-the-art technologies and a raft of innovative ideas right across the board. In short, the BMW 750i’s 12-cylinder engine had been built with the aim of setting a new and groundbreaking benchmark that would occupy the highest echelons of automotive engineering.