Wheels-Tires Do These Tires Make Me Look Fat?

[Gearbanger 101]

tire size isnt the issue it is the backspacing of the rim that dictates tire size you can use on a fox.

Yes and no.

Unless you want to make some major adjustments to the front fenders and the fender bracing, a 9" wheel with a 255 is the absolute widest you're going to get away with. Problem is that with more back spacing, the tire and wheel bulges out past the fender lip, making it look awful. With less backspacing, the wheel/tire contacts the lower control arm and/or the front shock (ask me how I know). I needed to "massage" the lower control arm a little to fix a little contact issue I was having.

Same goes for the rear. Unless you want to mini-tub and lose your tailpipes, you're not gonna get away with running much wider than a 10" wheel and tire combo. And all this is on a car that's only about 1/2" lower than stock. Guys who like to drop their cars 1" + are going to be in for a real headache!!!

I think the widest I've seen without contacting the inner fender was a 10.5" rim and a 315 tire in the rear....but it required a pile of work to make it fit.


Backspacing can only get you so far. If you don't have the real estate to work with, it really doesn't matter.

 

[jrichker]

Put the quad shocks back on if you took them off or don’t have them installed.

The quad shocks are a roll of the dice. No matter what the combination of tires, control arms and shocks, some cars will wheel hop without quad shocks and some won't. There are so many variables in 34-18 year old cars with wear, misalignment and combinations of suspension components and tires that one unchanging answer won't work for everyone.

I personally would install them, and make sure they are in good shape. I do know this, that Ford is cheap. If they could have made changes in some simple component like bushings or control arm construction and saved $10, they would have done it. Multiply $10 times all the Fox body Mustangs ever made and you would be almost as rich as Donald Trump. That's a lot of $$$, and good incentive to engineer something to do away with the quad shocks.

 

[FastDriver]

Problem is that with more back spacing, the tire and wheel bulges out past the fender lip, making it look awful. With less backspacing, the wheel/tire contacts the lower control arm and/or the front shock (ask me how I know).

Refreshing my memory on front wheel spacing... Even though it's old, I noticed this comment and thought I'd make a correction in case someone else comes along. I believe "more" backspacing, i.e. moving from 5.8" BS to 6.5" BS would bring the wheels/tires towards the center of the car, possibly causing contact issues with the inner fender and/or the A-arms on the front. "Less" BS, like going from 6.5" to 5.8", would push wheels/tires to the outside of the car and would increase the turning arch of the outer part. So, "less" BS would possibly cause the wheels/tires to stick out of the fender or rub the lips on the bumps, and it could also cause the outside of the tire to rub on the front of the wheel well at full lock. It's counter-intuitive because the greater the BS, the more inwards the wheel/tire shift. I think I've got this concept right, but if not, please correct me and show your source.

 

[Gearbanger 101]

Refreshing my memory on front wheel spacing... Even though it's old, I noticed this comment and thought I'd make a correction in case someone else comes along. I believe "more" backspacing, i.e. moving from 5.8" BS to 6.5" BS would bring the wheels/tires towards the center of the car, possibly causing contact issues with the inner fender and/or the A-arms on the front. "Less" BS, like going from 6.5" to 5.8", would push wheels/tires to the outside of the car and would increase the turning arch of the outer part. So, "less" BS would possibly cause the wheels/tires to stick out of the fender or rub the lips on the bumps, and it could also cause the outside of the tire to rub on the front of the wheel well at full lock. It's counter-intuitive because the greater the BS, the more inwards the wheel/tire shift. I think I've got this concept right, but if not, please correct me and show your source.

No, you're right. I should have said less backspacing, or more offset.

 

[elarm1]

do you happen to have a pic with the 275 tire and 10" rim?

 

[Gearbanger 101]

^ Yep....just like mine. Rim's sticking out past the tire. Makes you really careful when you're pulling up next to curbs.

 

[FastDriver]

No, you're right. I should have said less backspacing, or more offset.

Greater offset also brings the wheel/tire inward. Negative or less offset moves the wheel/tire outward. More backspacing and/or more offset would move the wheel inward, potentially causing suspension clearance issues with a given wheel.

It's unfortunate that we don't just go with one or the other measurement for standardization. Backspacing makes more sense to use since it is easily measured and does not need to be calculated. Also, backspacing gives you a very straightforward way of knowing if there is going to be a mechanical clearance issue between your suspension and the inner edge of your wheel. Offset does not.