kimmer

Want to go a little wider next season. I have 9.5x17 wheels and would like to run Kumho xs, 295x35x17. Would this size be ok to run on my wheels?

Solofast

Yes, we do to it all the time, no problem.

The 295's haven't been shown to be any faster than 275's. They feel more rubbery then the 275's.

kimmer

There must be a little better grip plus it will lower it a hair more. Don't like the sound of more rubbery though.

drivinhard

I know dodging cones in 2nd gear is a different animal, but for high speed road course stuff, I have found the above 100% true on both counts as well. I have tested back to back on the same track on the same day with various sizes. Both on a 10.5" wheel.

You're "rubbery" will go up a notch on a 9.5" wheel.

NASCAR314

I run the 285's on 17" x 9.5" wide wheels with good results. Fit is near perfect. But that won't get you any lower as they are still a 40 aspect ratio. Price is much lower on a 285 vs. 295

Solofast

You would think so, but every tire is different. What I mean by that is that even though two tires of the same make and compound are very similar, when you make them in two different sizes, they just work differently. Maybe the wider tire rolls more and doesn't put as much rubber on the road as the thinner one, or the tread radius is different, which causes different things to happen when cornering. Or the tread ply angles could be a little bit different. Or, as you add more width, the contact patch length goes down and you have to soften the tire to make it work (which may indeed be the case here). Anyway, it doesn't matter, whatever it is, the 295 hasn't been shown to be any faster than the 275.

It also plays into the "enough" tire rationale. Adding tire adds grip until you get "enough" tire. After that, more tires doesn't help much and too get the wider tires to work you end up dropping the pressure more and the response gets worse.

Lots of theories, but you have to respect that what works is what works, for whatever reason.

drivinhard

(probably one of the few)

kimmer

That makes a lot of sense and I read something awhile back that stated the same. The 275's are quite a bit less expensive and I will most likely go with them for my autox tires. I can use some of the extra $ to get my suspention right. Found the xs for $99 a piece.