The story behind BMW's unique quad-turbo diesel engine, its impressive performance, and how it stacked up against its rivals in the X5 M50d.

Apart from building iconic high-performance rides of its own, BMW has also supplied engines to other companies, which used them to power amazing supercars. Follow us: BMW production cars are reveared ...

BMW's M series of engines doesn't necessarily refer to the manufacturer's performance-oriented line of Motorsport models. M designates a line of engines that BMW offered in its cars from the mid-1970s ...