sms302

I have a 2012 GT with 18s and standard brakes, lowered about an inch.

Don't want to stagger, was thinking about 275/40/18s on 9.5 wheels all around and Tire Rack guy was not positive they wouldn't rub in the front. I know some people are/have run that size, any problems? Thanks

UrS4

Depends on front wheel offset. But you should be able to get 275 or 285/40/18 up front as long as the offset allows it. Old GT500 wheels are 18x9.5 ET45 offset and can easily do 255 as that is stock, would think Ford word build in enough wiggle room with that offset for a 275 tire. Might need to go to a 40 or 35 offset for 285 and be safe.

JAJ

I've run 275/40x18 Nitto NT-01's on 18x9.5 GT500 rims (the NT-01's are wide for 275's - almost as wide as most 285's) and there's no rubbing or contact, even with the fender liner bent to clear my brake ducts.

My 275/45x18 summer tires, on the other hand, do touch the fender liner where it's bent around the brake ducts when I make a full-lock turn, but not anywhere else and not in normal driving.

krazykevin

I run with 275/40r18 all around and have no rubbing running 40+ offset

sms302

Thanks everyone, all good info. i think the wheels I am considering have a 35 mm offset.

UPRSharad

35mm with what width?

I had the 18x9.5 w/ 275/40-18 combo on my car and it was nicely balanced.

sms302

Thats part of what I am trying to figure out, what is proper offset for the width?

UrS4

Here's a tip.

Go to tirerack.com, which is one of the forums sponsor. Type in the size tire you want and go to the spec sheet. It will give you a wheel width range and then an ideal rim width. Then enter in your cars info and look at wheels in those wheel width range and look at the offsets.

But the short answer is a 275/40/18 will fit on a 18x9, 18x9.5, and 18x10. The offsets will range from 30-35 for the 18x9. 35-45 for the 18x9.5 and 40-45 for the 18x10.

The smaller the offset number the closer the wheel will be sticking out away from the car possibly past being flush with the fender. The bigger the number, the more tucked into the car and closer to the suspension parts.

The problem is in the front. Some people get tire rubbing with a 18x10 wheel with a 45 offset, some don't. A safer bet would be a 275 tire mounted on a 18x9.5 wheel with a 40 offset.

Norm Peterson

Check with member 'Nuke'. He's running 275/40-18's on 18 x 9.5 GT500 wheels which I think are +45mm offset.

According to Vorshlag, 275/40's on Forgestar F14 wheels in 18 x 10 x +42 also clears everything (including Brembo brakes).


Norm

Nuke

My ears are itching...

I'm running 275/40/18's all around on my '07 with the '07 SVT GT500 wheels, 18" x 9.5", with stock suspension and no rubbing. HOWEVER, due to the wide rubber up front, the car will tramline a LOT on roads that have the slightest trough worn by heavy (typically truck) traffic. If I had to do it over again, I'd stagger with 255's up front and 285's in the back.

And my wheels are either 45 or 48 offset.