I have stock wheels. I've seen posts about going to a 255/40-18 tire. It looks real tight in there to me. Can someone confirm that this will work-clearance to strut, fender lips, etc., and general impressions?

 

I have 255x40x18's, G-max03 on mine, but I have 8" wheels. I have put a set of Michelin Pilot sports in 235x45x18 on stock SS wheels.

 

looks cool! def need to know regarding stock rims though.

 

The second part,..... I have put a set of Michelin Pilot sports in 235x45x18 on stock SS wheels. He loves them, they look good.

 

Not an SS, but same basic principle still applies, I'm running 245/40R18's on the Cobalt SS wheel's, +42 offset, 7" wide. Since a 255 would be 5mm on each side, I don't see any reason they wouldn't clear. But your rims are 1/2" wider (1/4" each side). But tire preferance could also make a differance as some brands run wider than others. Stay under 26.1 for height and you'll be fine there.

 

I am running stock rims on my SS (18x7.5) and 245x45x18 Nitto 555s.

The rear is no problem except the plastic splash guard is real close. In the front the tires are right up to the strut tower spring purch, especially tight on the passenger side. No taller tire will work with stock suspention, even with spacers. There is plenty of room between the tire and the fender.

I want to put 15mm spacers on all four corners soon to bring the sidewalls just to the edge of the fender. That will require four 15mm hub centric spacers and twenty new wheel studs 15mm longer than stock. The spacers are $180 for four and the studs are about $3 each plus shipping.

 

the 255/40-18 are the same diameter so the strut tower spring perch should be ok. Looks tight on the sidewall-to side of strut.

 

With the 255x40s and 5mm spacers there should be no clearance problems if the OEM tolerances are close. It is recommended to use an 8 inch wide wheel with 255 tires, but only one size over should work. 245s work with 7-9 inch rims.

 

Looks better if you lover it on KWv2's.

 

that pic is awesome!