[omar.ahmad0524]

I track my car and ruined the fronts by running them at incorrect pressure (excessive sidewall wear). Rears look fine however and are currently at 4/32" tread depth remaining

Wheels are stock and tires are Yokohama advan AD09 and tire sizes below with the new tire diameters as well.

Front : 225/40/18 (25.1")

Rear : 245/35/18 (24.8")

I want to see if I can safely change only the fronts since the rears look fine. The rears are at 4/32" tread remaining.

If I replace the fronts that means my front diameter will be 25.1" and the rears will be at (24.8 - 4/32) = 24.675".

This is a difference in diameter of 1.72%.

Is this fine for Xdrive vehicles? I track my car once a month in case the usage makes a difference.

[Fiesta ST to M240i]

4/32" isn't a whole lot of tread. Could even get sketchy in heavy rain. I'd just get 4 new tires. Even if it is alright, why do it? You're just going to need new rear tires not too far down the road then you'll have mismatched wear again.