07gte4j

I just purchased a set of SVT GT500 wheels they measure 18x9.5. I plan on running a set of Nitto NT555's. I would like to run a tire size of 245/40ZR18 all around. Right now I have stock rims with a tire size of 235/50R17. My concern is will 245/40ZR18 rub at all?

Andrew Christian

Honestly, you should be able to get away with 265s on 9.5 width tires all around. I wouldn't recommend it though, as a 265 in the front is way to wide to daily drive on with stock suspension. I would say do a 245 in the front and a 265 in the back. It'll also give it a nice staggered appearance.

If you want the same width all around, I would go with the 245mm.

Nuke

I currently have a set of 2007 SVT GT wheels, 18 x 9.5, on my 2007 GT with 275's all around with no rubbing. I'll never go 275's up front again due to the tramlining. 255's up front and 285's rear would suit me. Otherwise, she's solid as a rock at 135-140 Mph.

Simon1

Depending on the tire you pick, you can go as wide as 285 or so. I have 305s on a 10 inch wheel. Tire rack used to have a pretty good estimator of what fits what.

audioAl

My 2014 Cyclone runs 255/40/18 front & 275/40/18 yokohama S-Drives rear on american racing razors 18x9 rims.

waykooljr

You can use a tire calculator like this one to see the rim width for a tire...

Tire Size Calculator - Tire & Wheel Plus Sizing

You can usually get these specs from the tire manufacturers web site.

Take note of the rim width range; choosing a narrow rim width will improve ride quality, choosing a wide rim width will improve handling, choosing a rim width at the middle of the range will have good balance between ride quality and handling.

waykooljr

lol! Never mind me, I missed the point of your question, too early to be posting I guess!

Carry on!

Norm Peterson

The GT500 came straight from Ford with 255/45-18's up front.


I have a set of the same GT500 wheels with 255/45-18 Goodyear Asymmetrics on all four corners. They've been on the car for several seasons and are just about done, and I think they're going to get replaced by 265/40-18 Michelin Pilot Super Sport tires.


245/40-18 is a pretty short tire, even shorter than my 285/35-18 track tires (which are mounted on 18 x 11's all around, that needed a half-mm spacer and a little trimming of the rear tiedown/bumpstop brackets and the rear shock boots). I get no tramlining and no rubbing even under maximum braking or cornering out on the road course.


I looked a little further, and 245/40-18 is really too small of a tire for these cars in terms of load capacity. You can crutch this by running them at about 5 psi higher than what the door sticker tells you to be running the OE 235/50-18's at (IOW, if the sticker says 32, you'll need to run the 245/40-18's at 37).




Norm

Simon1

I liked the 245/40/18 when I had them because of the turn response in corners. But I didn't like how low it was in the front.

Dino Dino Bambino

Nope. I'm running 245/45R18s and I have room to spare. My next set will be 255/45R18 like the GT500's.