It is part of a modular BMW engine family, of straight-three (B38), straight-four (B48) and straight-six (B58) alloy block and head petrol engines,[1] which use a displacement of 400 cc (24.4 cu in) per cylinder in the 1.2 and 500 cc (30.5 cu in) per cylinder in the 1.5.

It specifically shares a lot of components with the BMW B37, due to their same size/configuration.

The B38 is used in front-wheel drive cars (such as the Mini Hatch and BMW 2 Series Active Tourer), as well as BMW's traditional rear-wheel drive and all-wheel drive (xDrive) configurations.

The first car to use the B38 is the BMW i8 hybrid sports coupé,[2] where it is used as a transverse mid-mounted engine.

[3] The B38 features direct injection, an 11:1 compression ratio,[4] variable valve timing (double-VANOS) and the single-scroll turbocharger with the world's first aluminium turbine housing,[5][6] manufactured by Continental.