What Works?
I loved the feel of the OEM wheels with the OEM tires. It just seemed so connected to the road. After I changed to the wider wheels, some of that feeling is gone.
I would like to hear from anyone who has switched to aftermarket wheels (preferably 19x9.5 and 20x11) and let me know what size tire you went to. Not what FITS. What WORKS.
I am torn between 255/35-19 and 295/30-20 (to go up only 10mm in cross section) and 265/35-19 and 305/30-20 (to go up 20mm in cross section). The wheels are 1" (25.4 mm, I think) wider than stock, so it seems logical that the wider tires (20mm increase) would work better as they are closer to the 25.4mm increase in wheel width. But the Michelins are spendy tires. So, before I sink any more of my lottery winnings (I wish) into new tires, I could use some real world advice.
thanks


Thanks for the good information. When I look at a stock Z51 wheel and tire, it seems that the sidewall is pretty vertical. On the wider wheels, the tire sidewalls are somewhat slanted inwards from the bead to the tread. I know that run-flats have a stiffer sidewall than non-runflats. I wonder if that has something to do with it.
Anyway. I would appreciate your input about sizes. up 10mm or 20mm in section width?

Anyway. I would appreciate your input about sizes. up 10mm or 20mm in section width?
I would go 20mm upsize...just be sure there is no rubbing on the inner fender plastic. Like I said, you are adding just 10 mm to the inboard side (where possible interference exists). You can look at your car right now and see what you have to work with, or try putting your hand over the tire and feel the clearance.
I ran 305s in the rear of my C5 and they worked fine, and looked massive from the rear....almost gave the '5th wheel' truck appearance, but I liked it....very common upgrade for the rear. The C7 will be different, but perhaps it will work.
Adding 10mm to the outboard size may look a bit passed the fender, but no one really agrees on where to make that call because the fender is not perfectly straight/parallel with the plane of the tire face. So, it's your call. Personally, I think a small protrusion is fine...it all depends where you stand when looking for it.




