While you’ve likely never heard of BMW’s B57S powerplant, there’s more than meets the eye. This engine isn’t just a collection of numbers with a BMW badge slapped on it. The B57S is one of the only quad-turbocharged diesel engines in existence. Set to be discontinued in September, BMW gave it the send-off it deserves.

Through the might of German engineering, the B Series provides superior efficiency and power in the diesel game. The engine nearly gave the Bavarian automaker the magic 621-mile (1,000-kilometre) range figure and did so while producing a substantial amount of power. BMW says the quad-turbo swan-song produces 400 bhp (298 kilowatts). 

BMW Final Edition

So why did the engine meet its fate? Long story short, the astronomical rise of emissions requirements ended the run of the B Series. Along with being too rough on the polar bears, the powerplant’s complexity led to abnormally high running costs.

Although the unique diesel was fitted to quite a few BMWs, the Bavarian automaker chose to honour it with a Final Edition of the X7 and X5 M50d. While you might think that BMW would just slap some badges on its M50d vehicles and be done with it, you’d be wrong.

Production numbers of the Final Edition models are still unknown but don’t worry, the vehicle will receive some special features. Driver aids like laser light headlamps, gesture control, and autonomous driving assistants are in the mix. Don’t get too excited though, as BMW says these SUVs will only be available in certain European countries.