GMB Racing

I am planning larger rear tires on my 15 gt w/ 235/50/18 tires,. What is the largest rear tire that will fit with the stock rims?

bluebeastsrt

285/40/18 will fit. But will buldge over the rim a little.

Derf00

Are you sure? It depends on what the rim width is. For 05+ Mustangs a stock 235/50 R18 size is usually on a 18x8 rim. The sources I find confirm the same for the S550. 285 would be too fat for that rim. You'd need at least an 8.5 although 9 would be ideal.

255 will easily fit 275 is pushing it. 285...pass.


http://www.mustang6g.com/forums/showthread.php?t=7703
http://www.latemodelrestoration.com/...eel-Tire-Guide
http://www.discounttire.com/dtcs/tir...T%7Cpc%7C85286

bluebeastsrt

I run a 285 series drag radial so I'm sure some will fit. It's a common set up on the SVT forum for drag radials. It may not be optimal if your a corner carver.

redass02gt

285s are generally not spec'd to fit an 8" rim. Go to tirerack and they're all spec'd for 9.5"+ rims. Maybe drag radials will fit because they have softer rubber and sidewalls.

bluebeastsrt

Yes I've read the "correct specs". However People all over the world are not following those specs to a tee and the tires don't fall off the wheels. The lowered crowd stretch a small tire over a wheel to decrease sidewall. Racers will go with a bigger tire on smallish wheels with no ill effects. I've run a 285 nitto 555R on a 8 inch wheel and cut 1.5 sixtys.It does buldge about half an inch but that wasn't a deal breaker for me considering I got the wheels for free! Some people look at the tires racks recommendations as law. Some look at them as recommendations. A drag radial is basically the same as any other performance tire. Just a stickier compound rubber. Here's a few links of performance car forums running 275-285 series and larger tires. So again I'm saying it can and has been done countless times. One thing everyone should keep in mind. Not all 285 series tires are created equal. A 285 nitto is smaller then the exact same goodyear tire. You really need to look into the dementions of the tire your buying. Some tires are half and inch wider or 3/4 of an inch taller but still have the same size stamped on the sidewall. In any event I geve my opinion of the absolutle largest. The OP can always compromise and go with a 255 or 275 series tire.

http://ls1tech.com/forums/wheels-tir...-inch-rim.html

http://forums.corral.net/forums/s-19...8x8-wheel.html

https://mustangforums.com/forum/4-6l...x-8-wheel.html

COMPORNG_15

what about on the 19" wheel how wide can I go? I wanna get fat in that back!

bluebeastsrt

It depends on how wide that 19 inch wheel is. You'll probably be able to fit a 305-315 series tire out back and since your changing wheels you don't have to worry about any funky fitment issues. on an 11 inch wheel will probably look sick.

redass02gt

Drag radials have a softer sidewall than the equivalent performance tire would have. That's why they relatively suck for cornering and are good for launching in a line.

Just because you can stuff a tire on a rim doesn't mean it will result in the maximum tire contact patch. Doing it for the look vs. doing it for proper handling are different. Do you think tire manufacturers just have nothing better to do than publish random specs? There's a reason they have a spec sheet, and it's not because they just have too much time and money with nothing else to do other than hit the numbers on a keyboard.

bluebeastsrt

Were just going to have to agree to disagree. You run what you want and follow ever recommendation. I'll continue to cut 1.5 sixths on my 285s and 8 inch wheels and run 9s in the 1/4. The original question was what's the biggest tire that will fit. Not what does tire rack recomend. I simply answered the question based on my personal experience. The OP is a big boy and will have to make up his own mind. We've already made up ours.