New Tire Size for 437m Wheels

[f82Haze]

I’ve heard things about going to a wider setup on the stock 19” wheels will cause TC issues as well as speedometer being off? I’m currently on PSS 255 275/35/19 and have PS4S 265 285/35/19 on order. Will the 10mm change affect the car too much? Thanks!

[M3SQRD]

The 265/35-19 and 285/35-19 are the widest tires you should run on the 437M 9” and 10” wide wheels. Wider would likely result in a loss of performance. The difference in tire diameters front and rear are 0.3” larger in diameter at the front and rear. That’s not going to affect TC and your speedometer (difference is negligible. For example, the % diff of the front = (dia265 - dia255) / dia255 x 100 = (26.3 - 26.0) / 26.0 x 100 =1.15%. If your speedometer is reading 60 mph, your actual speed is 60.6 mph.

[N1rve]

Originally Posted by f82Haze

I’ve heard things about going to a wider setup on the stock 19” wheels will cause TC issues as well as speedometer being off? I’m currently on PSS 255 275/35/19 and have PS4S 265 285/35/19 on order. Will the 10mm change affect the car too much? Thanks!

265/285 would not cause TC issues (I have no idea who has been saying that). In fact it improves traction with less wheel spin and is the most recommended tire size.

Your speedometer will be off by like less than 1 MPH so there isn’t much to compensate for.

[BigFatRaccoon]

I run 265/35/19 and 285/35/19 PS4s and I definitely recommend it. Car handles and grips way better, night and day difference, rear end kicks out way less in corners, and no issues with MDM mode or wheel spinning. However, like others have said, it's not recommended to go above 285 for the stock 437ms rears.

The speedometer isn't something to be worried about. In fact, all modern BMWs read +2mph higher on the cluster than actual speed from factory so this maybe changes that less than 1mph at most on the readout.