245/40/18s all around on a 330i ZHP

[KrisL]

Thoughts? I'm thinking it would cancel the slight factory understeer on the ZHP. Anyone done this? Any clearance issues? 245 should be an OK width for both the 8" (front) and the 8.5" (rear) wheels...

[Raffi]

I ran 255s in the rear before getting my coilovers, so you should be ok. I'll let others comment on the front size.

[KrisL]

I ran 255s in the rear before getting my coilovers, so you should be ok. I'll let others comment on the front size.


255 rears are the OEM size on ZHPs :)

[Gary@Tirerack]

Did you run 255/40R18? or 255/35R18..?

[Andy]

I’m currently running 255/35/18s all the way around on my OEM 135M wheels with no problems.

Running a 245/40/18 is going to make your tire 1/2" taller then the OEM size (255/35/18), which IMO, is too tall. It may fit without rubbing, but your going to hurt your performance a bit. I think you’d be better off running a 245/35/18 or a 255/35/18 all the way around.

I'll probably switch to 245/35/18s on my next set.

[KrisL]

I'll probably switch to 245/35/18s on my next set.


Great, thanks. Why the switch from 255 to 245?

[Nick325xiT 5spd]

You won't cancel the factory understeer without camber.

[Andy]

Great, thanks. Why the switch from 255 to 245?
Slightly better gearing, lower profile tire, lighter and most importantly legal for the STX class I’ll be running in this year.


You won't cancel the factory understeer without camber.
I agree. Same size tire all the way around will help a lot, but it won’t eliminate the understeer completely.

[RSPDiver]

Call me crazy, but I was contemplating trying to go a bit wider on the rears (stock wheels) when the time comes. The stockers don't seem to protect the rims much, like the stock M Roadster/Coupe rear sizes, as evidenced by a scratch already placed on my right rear on a seemingly non-trecherous pavement anomaly. Of course, I'm thinking of upping the front a touch, also. Maybe 245s. I don't track, so street survival is more important to me.