Mrbluedevil88

As title states, guys that are running a 18x9 front wheel what tire size do you reccomend? This is going on a c6 grand sport

USAZR1

Most 275's will work fine, on a 9" width wheel.

0Finspeed

In a perfect world, you want to get the tread width of the tire to within 1/2" of the rim width. All tires in a given size will vary a good bit on actual tread width. For instance, the Hoosier A/R7 275/18 has a 10.3" tread width. It will fit on a 9" wheel, and you can run it, but it's probably as big as we would recommend. A 10" or 10.5" wheel in that case, would be optimal. The 245/18 Hoosier for example, has a 9.4" tread width and would be about perfect for a 9" wheel. Just check the specific tread width of the tires you are interested in running and go from there.

USAZR1

The average 275/35/18 street tire will have a 11"-11.2" section width and a 9.6"-9.7" tread width and almost all have a manufacturer's recommended rim width range from 9"-11". Yes, a 10" width would be optimum but the average driver will probably not be able to tell the difference. If we're splitting hairs, a 255 tire would be almost optimum, on a 9" width wheel.

The majority of C6 Grand Sports will have a wider front wheel than 9", anyway.

0Finspeed

No disagreement here. My examples were DOT R comps which typically measure out wider than a street tire. Thus my comment about a given "X" size having many different actual measurements and checking the specs for each example. Getting the bead seat area of the wheel supporting the sidewall/shoulder of the tire vertically makes a huge different in steering turn in feel and overall "crispness".