I am gooing to by a new sett of wheels for my Evo 8 during the winter. I have KW V3 coilovers, sway bars and som other bits on and is about to go FP red on pump gas. Use is track days and summer dry and wet(damp). So I was looking to get 235-40/18 Pilot Sport Cup tires on a new sett og 18x8.5" +30 This will give me a few extra mm track width over the OEM wheels.
So the question is there a need to go bigger 245-265?? Or is 235 enough?

 

Really won't see a large difference between the 235 and 245 size. Only 1/4" per side, 1/2" overall width difference. 265's will be a bit aggressive w/out a fender mod. Also don't see the Sport Cup made in a 245 so makes the choice a little easier.

 

Is there a big difference regarding the grip/feling between 235 and 265? Or is it just for looks 9.5" and 265 are so popular?

 

Yes, I would say noticeable difference in those two sizes.

 

Ultimate grip will be higher on the 265s, but depending on sidewall height, turn-in response will be quicker on the 235s. Personally, for track use, I would get the widest tires to maximize my ultimate grip.

 

fit as wide of a tire as your car allows. wider is better in most instances. that's if you don't mind rolling fenders and possible having more neg. camber.

 

I would also stick with 17" wheels, the tires are SO much more resonable. I use stock enkeis for my track wheels and I have 18s for street. I paid $136/tire for NT01s in 245/40/17.

 

Great answers from a lot of the guys. I agree that wider is better for increased grip, however, it also depends on which tire you choose and the treadwear (compound) rating. I think your ideal setup is the 265 tire on a 9.5" rim. Going any less will not give you the noticeable improvement you will be looking for.

I use 265/35/18 BFG R1's in the dry and Hankook RS2 in the wet. I have my car lowered, and rolled the fenders, although I don't think I needed to so for the 265's. A bit of minor fender liner rubbing in the front where the only issues. That can easily be trimmed away.

For my winter project, I'm now moving up by 1/2" wider, to 18xs10.0 wheels and am hoping to fit 285/30/18 Hoosier R6 tires. My camber is -3.0F / -2.0R. Negative camber will help you fit the wider tires more easily.

 

If you are tracking the car and you have been for some time..... move up to an R-compound tire. A 245/45/17 R-comp will be leaps and bounds better than a 265/35/18 street tire. Odds are it will be cheaper and lighter as well.

I'm running 255/40/17 BFG R1s on BBS rims and they have a ridiculous amount of grip. The BBS rims are super strong and light. I would try a smaller R-comp first. You may never look back.