New car review: BMW X6 M50d
For BMW, the M brand - for motorsport - is the pinnacle of performance and one defined by the racetrack-ready M3 and M5, two of the fastest cars on the road.
Such is the M division's success that BMW was keen to further exploit the letter, so is dipping its toe in the water with a new range of M Performance models.
To the uninitiated, the difference between M and M Performance is tricky, given each relies on the same red and blue badge and each features the M in its name.
But M Performance is a rung down on the sports scale, making them more affordable - and not quite as quick. Or sporty.
It also allows BMW to break some of the M rules, like using a diesel engine in the M50d versions of the X5 and X6 soft-roaders.