Best wheel/tire size for roadcourse

[ajderzie]

I'm not quite sure if all these wheel sizes are for looks, dragging, autocross, or track racing. What is the optimum front, real wheel size and tire size for the fastest track times (roadcourse)? This is for my C5 coupe with z51. Thanks!

[Luke@tirerack]

Here's what I would suggest

17X9.5 5-475 ET55
P275/40R17

18X10.5 5-4.75 ET62
P305/30R18

[andy82]

I'm looking for auto-x tires too and have the same basic problem. Unfortunately there is no 305 Kumo (or Hoosier), only 315 and these are probably to wide to mount on the 18x10.5, right?

Andy

[Luke@tirerack]

Hoosiers are available in the 305/30-18 and the Pilot Sport Cup is also