Will these tires fit?

Mrdestination28 · #1 (**permalink**) 09-30-09, 12:14 PM

I don' know too much about tire sizes and the possibilities of fitting different sizes than original sizes. I have the 18 inch tire package but I was wondering if a 255/45R18 or 245/45R18 or 235/40R18 tire would fit on the rim and not stick out of the car.

I am looking at getting the Yokohama S. Drive tires BTW and was wondering what everyone else has on their stock 18 inch rims.

Thanks in advance

Zymurgy · #2 (**permalink**) 09-30-09, 04:49 PM

The 255/45 will be slightly smaller in diameter than stock - speedometer error of less than 1%
The 245/45 will be smaller in diameter by about 2%
The 235/40 will be significantly smaller in diameter - about 7%. If your speedometer reads 60mph, you'll actually be going about 56mph.

The section widths are all within about 0.5", so you'll only be modestly wider - should be no problem staying within the wheel wells. All the mentioned tires are also rated for use on 8" wide rims, so again, no problems.

Mrdestination28 · #3 (**permalink**) 10-01-09, 02:57 AM

Well those sizes are for the Yokohama S Drive but I am also looking at the Pirelli PZero Nero M&S which have the sizes 255/45ZR18 and 245/45ZR18 and I am also checking the Pirelli PZero All Season tires which have the original equipment size of 235/50ZR18.

All in all would you guys suggest that I stick with the original equipment sizes on the car or will I be safe using the 255 size? I would like to have a bit more width on my tires but I don't want them to pop out. What should I do?

Mrdestination28 · #4 (**permalink**) 10-03-09, 04:38 AM

Look, I know these are probably stupid questions but could I at least get a response?

b4z · #5 (**permalink**) 10-03-09, 08:43 AM

They will definitely fit without sticking out. Keep in mind that the CTS-V has 285s at the rear and i think the wheelwell can take an even wider wheel.
Just try to keep the overall diameter of the tire within a few percent of the
Oem package so that your speedo won't be too off.

tiger4life80 · #6 (**permalink**) 10-06-09, 04:37 PM

if this helps, i just got aftermarket wheels, the tires are 255/35/zr20's and i have no speedometer error, checked with multiple gps's simultaneously and they fit the fener wells nicely, you can see my pictures.