pntrackman

What front and rear tire sizes can I run on 18 inch wheels for the track on a 2005 C6 and not have Active Handling system issues?

I like a particular OZ Racing wheel that recommends 245/40-18 front and 275/40-18 rear.

Curious if I could use the R6 in 245/40-18 or 245/35-18 on the fronts and either a 285/30, 295/30, or 295/40 on the rears without AH issues?

Experienced HPDE driver in P-cars and have not dealt with staggered wheel diameters before.

pntrackman

Using information on other threads on this issue to further update my question. Other thread on this topic indicates a front diameter that is .942 to .99 of the rear diameter should work and a 245/40-18 front with 295/30-18 rear fits within that range .

By my math the front wheels need a height in inches between 3.282 and 3.449 to fit .942 to .99 of the rears and a 245/35 should be 3.375 inches in height (aspect ratio).

Any feedback from someone that is running 18's on a C6 that has done this already and can confirm this is correct would be appreciated.

gkmccready

I run 275/35r18+305/35r18 on 18x10+18x11 CCW C140s and I can leave all the nannies on for street driving without an issue. Opinions seem to vary, but if you keep the rear at least 1/2" taller than the front you should be in okay shape. I also ran 295/30r18+305/35r18 for a while without nanny troubles.

AU N EGL

Dont get too hung up and numbers or ratios like guys post in other threads.

as long as the rear tire O.D. is slightly larger then the front tire O.D. ie 1/4" - 3/8" or larger YOUR FINE.