225/45R18 front · 255/40R18 rear

BMW’s approval. A star on the tyre wall means BMW tested that tyre for your model — around 50 checks, from grip and braking to wear, noise and high speed, well beyond the EU tyre label.

Not the law. A tyre without the star, in the right size and rating, is safe and legal and passes the NCT.

Why it matters most on xDrive (four-wheel drive). The front and back wheels are driven together, and the drive system allows only a tiny difference in how far each tyre travels per turn. Star tyres are made to BMW’s own measurements so all four roll alike; two tyres with the same size printed on them, from different makers, can differ by a few millimetres.

So on xDrive, keep all four the same: star on all four or none, and the front and back within about 3 mm of tread of each other. Mixing them is what wears the transfer case — and BMW dealers check it before a transfer-case warranty claim.

What we do. BMW’s star sets come first. The others fit and perform fine as a full set of four, and on xDrive we never fit a pair against star tyres on the other axle.