Jgavinsop

I have a 2015 GT premium currently with 275/40 R19's on the back and 255/40 R19's on the front. I'd like to swap them out for 255/50 R19's for the winter but I'm not sure if they will rub. Anyone ever try this tire size?

Buck Sergeant

It has been shown a S550 Mustang can comfortably accommodate a 315 tire in the back and a 305 wide tire in the front. Running a 315 tire requires no modifications for clearance, (only requires a rim wide enough to mount it: minimum 10 inches) and the same goes for the 305 width up front. I feel confident if 305 and 315s will clear with no modifications, as long as the ride heights stay OEM, 255/50x19 should not be a issue. Post this issue on the S550 link, you should get a bunch of answers.

Norm Peterson

If your front 255/40-19 tires fit underneath the lower spring seats on the struts (rather than beside them), you'll want there to be more than an inch and a quarter room in the vertical direction even if you're comfortable about running tight tire clearances.

I don't think I'd ever buy tires that were 2" taller than the tires that came on the car.


Norm

Buck Sergeant

Norm makes a good point. On my 2014 GT I upgraded from 8 inch "tread width," to 11.4" tread width., in the rear. It was tricky, but the 11.4" tread width was the same diameter as the OEM 245/19 OEM tires; which was approximately 27.1 inches tall. If you want more "sidewall" which is great in the rear tires, great stored up energy, to improve that 1.9 sixty footer, then you should seriously consider a gear change. With my 11.4" tread width , I went from the 3:15 OEM gears, auto, to 3:55 gears. Of course, a Circle-D converter in conjunction with the wider tires seriously improved my 60 footers. Also, Norm is right about clearance in the front. I have run front tires with a quarter inch clearance, but any metal in sight was rounded off with my trusty grinder. Remember, I do NOT advocate close clearances front or rear. I am just describing my insanity with racing. Presently I am running Continental Contisport Contact 5P , 235/45ZR19 in the front, these shoes are 6.5" tread width and 27.3 Diameter. Hope I didn't get to carried away.

Norm Peterson

A quarter inch is a ton of room . . . . (no, it didn't rub) Different level of insanity, I guess.










Norm