When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
You can do 18's all around, but you cannot get tire sizes that are the same for front and rear because there is almost an inch difference in overall diameter between front and rear tires stock. You need to keep the ratio the same or close to keep from having ABS/Traction Control and AH issues. Most guys go for 18's all around for looks and having a slightly shorter sidewall in front will give you better steering response. If you are going to go with 18's all around I would recommend upgrading to 18/11 rear and 18/9.5 or 10 front. Put on 295/35/s in the rear and 265/35's up front and you won't have any AH or Trac-control/ABS issues.
Here's an idea that I did to my 00 Coupe. Put the rear 9.5 rims on the front with 265/35/18's and bought 2 new 18x10.5 same style rims for the rear and put on 295/35's. Very nice looks and ride,
Fred K.
You bring up a good point about different overall tire diameters (front is one inch less than rear on the stock layout). My intent was to obtain the capability of rotating the tires front to rear. Unless they are the same geometry, you would not want to rotate them. This would keep me from my original intent. Wonder what GM says about running with the same size tires front & rear?
Are you running the same diameters front & rear? Read the post from Corey who says there could be problems with the ABS if the size ratio is different from stock. Stock setup shows rears to be one inch taller than fronts (26.66 inches vs 25.68 inches).
If you ran the same diameter tire front and rear you would likely have code problems. More importantly the car would look bad. The fronts would look too big and the rears would look too small. It would not be subtle. 18's all around are not a problem at all. Just not for what you are trying to attain.