e46 M3 Tire Sizing Thread

[crbws6]

Looking at:

245/35/19 (25.8" dia) Front
265/30/19 (25.3" dia) Rear

0.5" diameter delta (2%)

Will this be OK for street use with respect to DSC?

[Tbonem3]

No that's E9x tire spec. Go with 245 & 275 or 235 & 265.

Also, .5" diameter is large. Look at rolling circumferences in the first post.

[RedM3/4]

In this thread looking for something else, but my experience is you need to keep variance really close if the rears are smaller than fronts; rears being BIGGER diameter/circumference than fronts isn't an issue within reason. I believe I've run 1/2" larger in rear with zero dsc issues. My belief is the dsc thinks rears are spinning under accel if the rears are turning much faster than the fronts, so with larger rears, this comparison is never going to trip unless real spinning occurs. There could also be some sort of "out of range" comparison too that would be an issue if rears were abnormally larger, not sure.

ADS

[Fresh1179]

I don't mean to inject additional variables but can someone confirm that an 18x10 et 25 with 275's will fit without rubbing given the proper camber setup. I would like to eliminate spacers on my track car.

[oceansize]

I don't mean to inject additional variables but can someone confirm that an 18x10 et 25 with 275's will fit without rubbing given the proper camber setup. I would like to eliminate spacers on my track car.

Yes, 275 18x10 et 25 is the standard rear flush with no spacers or rubbing setup.

[lvm3sm46]

18x10.5 +34 will they fit on the rear?

[narudnad]

Can someone advise if 18x9.5 +22 fit on our cars without any issues? And if so, what tire size you may recommend? TIA!!

[Thoglan]

Can someone advise if 18x9.5 +22 fit on our cars without any issues? And if so, what tire size you may recommend? TIA!!

Depends what you mean by no problem. 18x9.5 et22 with 265/35 is a very common size. It is very aggressive on the front though. Requires at least 3 degrees of negative camber, which is pretty compromised for a street car.

[narudnad]

Depends what you mean by no problem. 18x9.5 et22 with 265/35 is a very common size. It is very aggressive on the front though. Requires at least 3 degrees of negative camber, which is pretty compromised for a street car.

Thanks for quick reply! By “no issues” I meant like the need for spacers and or rolling/cutting fenders etc. My car is not daily driven and experiences the occasional track day or canyon most of the time. I always have a hard time understanding these wheel specs lol but is x9.5 +22 any more or less aggressive than a x10 +25?

[Tbonem3]

9.5 to 10" is a half inch or 12.7mm. So on both sides of the wheel, the 10" with stick 6mm farther out. With 25 offset, the whole wheel will come in 3mm more than the et22 wheel. The final result will be that the 10" wheel sticks out 3mm more than the 9.5" wheel, but the inside will also be 9mm farther in.

A 10" wheel is harder to fit more due to the inside than outside. If you can fit the 9.5et22 up front, because you have camber plates, you can fit the 10" . The bigger issue will be innner rubbing on suspension.

[narudnad]

9.5 to 10" is a half inch or 12.7mm. So on both sides of the wheel, the 10" with stick 6mm farther out. With 25 offset, the whole wheel will come in 3mm more than the et22 wheel. The final result will be that the 10" wheel sticks out 3mm more than the 9.5" wheel, but the inside will also be 9mm farther in.

A 10" wheel is harder to fit more due to the inside than outside. If you can fit the 9.5et22 up front, because you have camber plates, you can fit the 10" . The bigger issue will be innner rubbing on suspension.

So your saying with the 9.5+22 I will have inner coilover rubbing? Therefore needing a spacer up front? What about rears?

[narudnad]

I’ve got a line on some wheels that I have been looking for in the color I want lol. So just trying to determine how much work I will need to do to make them fit before I send the $$$. Thanks for all your help!!

[Tbonem3]

So your saying with the 9.5+22 I will have inner coilover rubbing? Therefore needing a spacer up front? What about rears?

No, I'm saying the 10" is more likely to rub on the inside than 9.5". The 9.5, despite being narrower than 10" is about as difficult to fit within the fender. But at least it's much less likely to rub the strut.

There's more to it than that - tire choice, strut brand, spring length - is your perch above the tire or not?

[narudnad]

No, I'm saying the 10" is more likely to rub on the inside than 9.5". The 9.5, despite being narrower than 10" is about as difficult to fit within the fender. But at least it's much less likely to rub the strut.

There's more to it than that - tire choice, strut brand, spring length - is your perch above the tire or not?

I can’t remember if the perch is or isn’t atm. I have ohlins on right now. 265/35 was my plan.

I have the option to go with 18x10 +25, there just not in my preferred color.

[Tbonem3]

Maybe try searching "ohlins" and "perch" and or "tire" "rubbing" Lots of ppl have ohlins now, but I can't quite remember what they've posted in regards to inner tire rubbing.

I wouldn't run a 10" front wheel unless it's a full track car with aero.