Nuke

I'll be receiving 4, GT500 SVT 18" x 9.5" wheels off of an '08 Shelby in a few days and am looking for recommendations on tire SIZES. My stock 18" fan blades have 235/50's on them and although they'd fit the new wheels I want wider rubber, especially on the back.

I was thinking 255/45's up front and 285/40's on the back. Pros, cons suggestions?

Thanks

Norm Peterson

You could also do 255/45's all around if maintaining the ability to occasionally rotate tires front to back matters. Under some conditions, the all 255/45 setup may exhibit fractionally less understeer (the GT500 can simply overwhelm the rear tires with torqueif you so choose, so it's less apparent when you run staggered tire sizesin that situation).

If a tire that's about 0.2" to 0.4" shorter doesn't matter, that opens up 245/45-18 and 275/40-18 as possible candidates. Probably with a psi or two additional inflation, since they are slightly smaller and have lower load index numbers, and there's maybe another reason as well. I don't *think* that small of a tire diameter difference would be particuilarly noticeable, and I wouldn't worry about the 1.3% speedometer effect at all.

I don't know if either the 275/40 or the 285/40 is verified for all possible conditions of wheel travel and steering angle if you have any thoughts of running the bigger rubber at all four corners.


Norm

Nuke

I've decided on 255/40's up front and 275/40's on the back. [sm=closed.gif]

Thanks!

sonnier

The 275/40s all the way around work fine. I'm running that size with a ProKit drop and haven't had any issues at all. After all that's what Steeda and Roush both put on their cars.

Nuke

Thanks for the input. It's good to know the 275's would work all the way around. I like the look of beefier-in-the-back so I'll be putting the 255's up front. I'd be a bit concerend with 275's up front giving the sterring a "heavier" feel.

sonnier

No heavier feel for me and the setup works great on track. Plus it's nice to be able to rotate tires.