Tire Setup

[jackliu0527]

Originally Posted by upstate650

A 295/30/20 tire is 27" tall. So is a 255/35/20, which is why they are a perfect match.

A 285/30/20 is only 26.7" tall, so you are starting out with a difference of just over 1% when the tires are brand new.

Tread depth is 10mm. At half wear on the 285/30, the tire will only be 26.3-26.4" tall. If the front are wearing half as fast at the rears, the front tire is now 26.8-26.9" tall. The difference is around half an inch, which is approximately 2%.

The generally accepted limits in tire height difference for the x drive system is 1%. But this applies at every point during the life cycle of the tires. So if you start out with a 1% difference, you need to know what will happen to that percentage over time. On the 6 series, the height difference will increase over time because the rears wear faster than the front, and on the setup you are using the rear is already the smaller tire.

I've run through 3 sets of rears and one set of fronts on my car with 255/35 front and 295/30 rear with no issues.

Several people have tried running 255/35 and 285/30 and have reported issues. Its your car, though, so do what you want.

the 245/35/20 and 285/30/20 are only off by .1 inch and are probably the best solution if you want to use the 373 wheels.

I can't explain why BMW sells the 245/275 set up. They are violating their own recommendations. Unless that set up doesn't come on x drive vehicles? I honestly don't know if it is only on RWD vehicles or both RWD and xdrive.

Haha its beyond me too, I have no idea why the tires comes like that, BMW only sells Xdrives in canada, I dont think you can get a RWD here unless its an M, and on the Xdrive models it comes with 245/275 it even says to use those tires on driver side door jam sticker

[mbp]

Hello all, I'm looking at putting 433M replica wheels on my 16 650 GC XDrive. The fronts are 8.5", rears 9.5". ET 33/37.

Would you recommend 255/35/20 and 295/30/20 for tire size? Are the 8.5/ 9.5 wheels wide enough for the these tires? Do you think I'll get tire rub at this size?

@upstate650, I see that's what you're using, but you have the wider wheels.

Thanks for the input.

[Cryptikz]

Originally Posted by mbp

Hello all, I'm looking at putting 433M replica wheels on my 16 650 GC XDrive. The fronts are 8.5", rears 9.5". ET 33/37.

Would you recommend 255/35/20 and 295/30/20 for tire size? Are the 8.5/ 9.5 wheels wide enough for the these tires? Do you think I'll get tire rub at this size?

@upstate650, I see that's what you're using, but you have the wider wheels.

Thanks for the input.

I'm curious too.

I have a wide body car with 305 rear tires, my rims are 12", I think it's just how my setup is I can't get wider tires, but I have wider wheels