Rear tire sizes

Topic: Rear tire sizes (Read 2316 times) previous topic - next topic

Rear tire sizes

July 13, 2021, 09:31:46 AM

Hey all, I thought this topic was beaten to death, but I can't seem to find the info any more since the site switch. Anyway, it's time for new tires on my bird and I think I may want to go wider. Have people ran 275/50r15s or 275/60r15s without rolling the fenders and retaining the quad shocks?

I can't decide between the 26" or the 28". I currently run 255/60r15s which are about 27. So if anyone has pics that would be very helpful.

Re: Rear tire sizes

Reply #1 – July 14, 2021, 09:32:29 PM

Not that I will be much help but obviously you have 15" diameter wheels but what is the width, backspacing and offset? If you are running a factory wheel let us know which one as someone may be running that same wheel and can chime in.

Re: Rear tire sizes

Reply #2 – July 15, 2021, 02:03:10 AM

When I had my Sport in it's final configuration, I had 275/40/17 on the back. No rolling, but the tires were fairly close IIRC. Quad shocks are a no-go unless you come up with some funky weird offset wheels, but then you'll tire protruding and probably other issues..

I had mine on Bullit wheels from something like an '03, '04 Mustang. The fit was perfect, too. Fronts were 245/45 and also fit well, no rubbing etc.

As an aside and not much relevance here, those same wheels/tires are now on my '87 Stang notch and unless I did body work, the combo is about as big as can be stuffed in there. One thing about The Tbirds...you can put a little more tire under it and have some wiggle room.

Re: Rear tire sizes

Reply #3 – July 18, 2021, 02:52:00 PM

I can't answer your question exactly, but I have a 275/35/18 on an 18x9 +35mm wheel. There is plenty of clearance to the fender lip and about a half inch to the quad shock.

You can kinda see the clearance to the fender lip in that picture.

Re: Rear tire sizes

Reply #4 – July 18, 2021, 10:40:22 PM

Thanks guys. I am unsure of backspacing. I got the wheels used, so I would need to pull them and measure. I will say they appear pretty centered with about 3/4" between either the quads or the lip. Thanks for the pic Shawn. I think I may have enough clearance to pull it off.

Re: Rear tire sizes

Reply #5 – July 19, 2021, 01:32:45 PM

Shawn....with Bullitt wheels I couldn't run the quads LOL. And I would've, had they fit. I had a pair of fairly new ones.

I also had CHE arms, so losing the quads in my case wasn't much of an issue. Anyway...your TC looks good!

Re: Rear tire sizes

Reply #6 – July 24, 2021, 01:33:06 PM

These wheels have an odd offset compared to what most people use on fox bodies.

Fox body Mustangs have far less room in the rear wheel wells, so they bring the tires in closer to the inner wheel well. If we ditch the quads and tail pipes, we can stuff a 10.5" wheel and a 315 in the rear.

Re: Rear tire sizes

Reply #7 – July 25, 2021, 03:12:58 AM

You're right on the Fox Stangs. Those tires of mine don't leave much room. Can't remember how little the gap is between the tire and shock on mine, but it ain't much.
I miss having a Tbird. Might have to start looking again...

Re: Rear tire sizes

Reply #8 – September 15, 2023, 01:28:46 AM

275/50r15s should fit great. I run 265/50 r 15s and I could of went wider. Rims 7 inch or wider.

https://tiresize.com/comparison/