BMW X3 M50

BMW people – the really committed ones, whose blood runs blue and white like some Bavarian-themed toothpaste – love to speak in code. You might be pretty up to speed on your chassis codes (E30s, F20s, G30s and the like), but you can always go a step further with engine codes. I won't get too far into the weeds here, but there's one that's worth knowing: B58. It's BMW's current 3.0-litre turbo petrol straight six, and headquarters should have a shrine devoted to the thing, because it makes everything it powers better.
You will find it in everything from the plug-in hybrid X5 xDrive50e to esoterica like the Morgan Plus Six and Ineos Grenadier, and it's just as adept in the big SUV as it is in the retro sports car. In the off-roader, maybe not so much.
Its more natural home is in stuff like the M340i or this, the M50 version of BMW's best-selling X3 SUV. We've previously driven the 2.0-litre four-cylinder petrol version of the new fourth-generation X3 and found a car with plenty of youthful style and practicality but that was short on some dynamic versatility and star quality. Put the B58 in and suddenly it all makes more sense.
This is an M Performance model, rather than a proper X3 M, but it feels surprisingly 'proper'. Nearly 400bhp and 0-62mph in 4.6sec is pretty serious stuff, and I think the B58 is a nicer engine than the M-spec S58. It's smoother, less laggy and doesn't sound like it runs on gravel. Response is outstanding and it shoves you forwards with very strong urge, while the familiar automatic 'box efficiently rifles through its eight gears.
This story is from the March 19, 2025 edition of Autocar UK.
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This story is from the March 19, 2025 edition of Autocar UK.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,500+ magazines and newspapers.
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