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[lordbmw]

I'll eventually get new rims and tires for my car but 1st want to run it by you folks.

I currently have the stock rims and tires (Bridgestone Potenza runflats) on my 335i xDrive coupe.

Current (Stock):

Front: 18x8.0 ET34 225/40/18 (Tire diameter 25.09)
Rear: 18x8.5 ET37 255/35/18 (Tire diameter 25.03)

I'm thinking of going to this:

Front: 18x8.5 ET35 235/40/18 (Tire diameter 25.4)
Rear: 18x9.5 ET35 265/35/18 (Tire diameter 25.3)

I think it'll work from everything I've read.

I don't want 19" rims due to the harsher ride quality and tire expense as well.

My car isn't lowered but I might do that sometime later but it won't be slammed, just mildly lowered when I decide to do it later.

What do you think?

[asquared]

You should be fine man. Im lowered on H&R cup kit and run basically your same setup with the exception my rear is ET40. I have zero rub. I have an LCI and I believe I can get by running a 5mm spacer in the rear, possibly a 10mm if I roll my fender.

[OnlyDriveGerman]

Search the threads for rolling diameter of different tire setups. Pretty good chart out there. You need to remain in 1% front to back, and I believe with an xi it's even more important.

[lordbmw]

Originally Posted by OnlyDriveGerman

Search the threads for rolling diameter of different tire setups. Pretty good chart out there. You need to remain in 1% front to back, and I believe with an xi it's even more important.

Then I think I should be good. There's not much difference between 25.4" (front diameter) and 25.3" (rear diameter). That's roughly 0.4% difference.

The BMW all wheel drive system must allow for some slippage between the wheels so I think I'm good.

[mweisdorfer]

Originally Posted by lordbmw

I'll eventually get new rims and tires for my car but 1st want to run it by you folks.

I currently have the stock rims and tires (Bridgestone Potenza runflats) on my 335i xDrive coupe.

Current (Stock):

Front: 18x8.0 ET34 225/40/18 (Tire diameter 25.09)
Rear: 18x8.5 ET37 255/35/18 (Tire diameter 25.03)

I'm thinking of going to this:

Front: 18x8.5 ET35 235/40/18 (Tire diameter 25.4)
Rear: 18x9.5 ET35 265/35/18 (Tire diameter 25.3)

I think it'll work from everything I've read.

I don't want 19" rims due to the harsher ride quality and tire expense as well.

My car isn't lowered but I might do that sometime later but it won't be slammed, just mildly lowered when I decide to do it later.

What do you think?

If you live in a state where the quality of roads is crap, I'd stay away from a 35 profile on the rear. Otherwise, you'll be replacing the rear tires and rims sooner than you think.

[asquared]

A 35 profile in the rear is standard on stock setup. My stock rears were 255/35/18. So going to 265/35/18 added slightly more sidewall anyways. It would be way too much in my opinion to go to 265/40/18