mfquinn

I have a 2008 C6 with stock size wheels and NON stock suspension. It is my daily driver that also is used for about 4 days a month on the track. I have read many posts and I have learned a lot, however I still have one question. I am pretty sure I have decided on the tires to purchase to replace my Firestone run flats. What I am confused about is size. It seems there could be many negatives with going to larger sizes. The stock sizes have a difference of 1.2" in diameter (front to rear). I have read about concerns with the electronics if the difference isn't the same. I have read posts about possible rubbing of brake ducts. I have read posts about possible understeer/oversteer issues with larger sizes. Larger sizes costs more. Larger sizes have larger contact patches which increases friction and decreases fuel mileage. I think you get what my confusion is.

So the question to you is what is the advantages to go with larger sizes? There must be some good reasons that Chevy chose the sizes they did. I just want to make as good an educated decision as I can. Thanks.

Solofast

There are lots of compromises that go into the OE tire selection. Not the least of these is aerodynamics and ride harshness. The base Corvette has smaller tires because of those two reasons, and the smaller front tires make a big difference in highway mileage and CAFE numbers.

For track duty you should upsize the front tires to a 275 section and the rears to a 295 (as a minimum) or greater. That's how much rubber it takes to get the front end to work.

DRUGschnorr

I do agree I started tracking w/ a 255 front and 295 rear.. after trashing those tires i went to 275 and 305's... much happier.... have use some 335's on rear but they rubbed too much on the fender (2008 C6).. thats what i get for trying 12in wide rear wheels..
now i use a 10 inch front and 11 in rear.... i like the 275 and 305 set up.. running toyo and Hoosier scrubs... i try keeping the size variance above one inch but it does not matter on the track.. i turn off all the nannys..
for DD i use 18 x 9 front w/ 255's or 275's and 19 x 11 rear w/ 305's and don't suffer too much milage decrease. My milage is more related to my heavy right foot than anyting else.

davidfarmer

larger tires don't necessarily give you much more contact area, but I feel that they help distribute load/wear/heat better. Much like a larger rotor can simply dissipate more heat, larger tires help dissipate the load of a larger-heavier-faster car.

The NASA TT gives have proven that smaller tires can work great, but for longer races etc, I feel larger tires will hold up better and be more consistent.

Compromises everywhere.......

drivinhard

I talked to a Hoosier engineer at PRI about this.

sperkins

And......??