i tried to search but not enough questions are asked. what is the max tire size

 

This has been covered many many times, and many members have many different ideas. IMO, yes, a 255/45/18 tire will fit in the back. Some will say you can squeeze a 275/40/18 tire on the stock 18" wheel. However, you will have severe tire buldge with this combo. 255/45/18 is the max tire you should put in the rear. You will maintain the stagger, and get a little bigger tire. You could also put a 245/40/18 in front and lose some of the understeer, and gain a wider tire in front, again maintaining the stagger.

Lou

 

+1 ^ wat he said.

 

when the stockers wear out im going to run 225/45/18 and 255/45/18.

 

With that combo, you'll increase the understeer slightly.

Lou

 

Won't this change the diameter of the wheel? I had oem 19s on 2005 coupe 6MT and they were just stolen so I started checking around for replacements. I wanted the same width all the way around to correct the factory understeer but I was told it would mess up the traction control because the diameter was smaller in the front and the computer knew that ratio difference. My plan was to get two sets of oem rears. The only choice is an aftermarket setup to maintain that diameter difference and acheive the same tire width right?

 

diameter and width is different.
diameter is 35-55 etc
width is 155-345 etc. you can change width all you want. the matter of it rubbing or not is the issue and fitting on a rim.

 

i'm running 265/40's on my stock rear 18's..

 

The 255/45/18 will increase the OD of the rear wheel by .3 of an inch or .01%. TC or VDC wont know the difference. Having a 245/40 in front and a 255/45 or 245/45 in the rear will maintain the stagger.

Lou

 

Alright thanks - curious to know when the TC / VDC starts sensing a difference
-bam

 

I felt the VDC gettin funky with 245/40/18s in the front. It was not an oem 8" wide rim, it was 8.5 inches if it matters

 

It shouldn't. I'm running an 8.5" in front with a 245/40/18, have been for 3 years. All is well. What size are you running on the rear, what width and offset on the wheel?

Lou

 

I gotta recheck the offset, but it looked fine in the wheel well. If I try it again, I would mount oem size on 8.5 wide rims on all fours. 225/40 should mount on that width

 

225/40 will be too small in outer diameter. Running the same size front and rear will kill the stagger and will give you problems with the VDC.

Lou