Advice on tire size for 18x9

[gotyorgoat]

I picked up some new wheels. 18x9 in the back and 18x8 in the front. I am thinking 245/45's in the front, but I want more meat in the back. I am looking for suggestions.

275/45/18
265/45/18
265/50/18
255/45/18
255/50/18

I think that I could create about .5" clearance from the face of the rim to the lip on the outside, so a 275 would be real tight. I am going to order on-line and would hate to make a $500 mistake.

Any advice would be appreciated.

[Z06vet]

A lot of things come into play here. I like a 275/35/18 on the rear and 245/40/18 front with those wheel sizes. This is on a 1st gen F-body. Looks like you have a GTO? I dont have any experience with that body style, but have seen a lot of 275s on the rear, and some a bit wider than that. Getting the correct wheel backspacing is important to fitting the widest tires. Have to conside your ride height as well. I see drum brakes, if you plan going to disc later, some dics will push the wheel out a little more than the drums. I always roll the fender lips to give a little more clearance and also prevent it from cutting into the tire if it does rub. I'm sure a few GTO guys will chime in to help you. Scott

[Mr Nick]

I have 18x9 front and rear on my 69 Cutlass, with 255/45 Front and 285/40 rear. The 285's have a slight 'bulge' but they work great. There is room to spare with the 285 on my car, not sure about your wheel well openings or backspacing.

If you want 245 up front, and your rear rims are 1" wider, I'd suggest at least a 265, preferably a 275 or 285 in the rear. 275/45/18 would be nice, but not a popular size. Continental makes the DW in that size I believe. Of course 275/40 rear would work, and is a popular size, and same overall diameter as 245/45 up front. Are you looking for some more sidewall in the rear, compared to the front?

[Mr Nick]

Have to conside your ride height as well. I see drum brakes, if you plan going to disc later, some dics will push the wheel out a little more than the drums.

Two very good points.

[gotyorgoat]

The car is a 67 Lemans and the wheels have 5.5" backspacing which was the deepest that I could find on a one-piece 9" rim. I think that I could create the space for a 275, max. I guess that I should see how much space I can make by rolling the fender lips and bashing the fenderwell out of the way and then make a decision. I do think that it will need to be lowered for a better stance so maybe the 275/40 with a drop is the way to go, especially if there is better tire selection vs the 275/45. I like the Nitto Invo's.

[Paul Huryk]

Clearance issues aside, a 9" wheel will support a 265 or 255 width tire. Not sure if there is much choice in 265 though.

[gotyorgoat]

I went with the 275/40/18 on a 9" wheel. Looks good with no bulge and no rubbing.