275/40 17 Problems...Help!??

[keepsbreakin]

I got some 275/40 17's for my GT. I have the wheels used on '03-'04 GT Prem. and 99-01 Cobra's. They are 17x8. I have seen guys with 17x8 put 275/40's on. My 275's won't fit. I have to take them to a tire shop to use another machine. Firestone said they could make the 275's fit, but the sides would bulge, the bead might not lock in well, and the wear pattern on the tire would be messed up. They said I would have less contact patch because of the squeezing on the rim. Every Stang with 8'' wheel and 275/40's has come back with complaints that the tires were worn out in 6 months, was what I was told. I asked what brand, and he said all of them. Yokohama's, Firestones, Bridgestones, etc.

What problems have any of you had with 275/40 on 8'' wheels? I don't want to have to buy 9''-10'' wheels. Am I stuck using 245/45's forever?

 

[mhanna77]

You need at least a 9" rim for the 275's with a recomendation of 9.5.
The recomended wheel size for the 245/40 is 8" with a range of 7.5-9.0, and 255/40 is recomended 9" with a range of 8.5-10

 

[keepsbreakin]

That is what Firestone said. But how come I see lots of Mustang guys with stock 17x8's and 275/40's? I know two personally with this combo, but neither listens to reason, and their words are always taken with a grain of salt...one of them had 285/40's DR's put on a 8'' wheel! They say 275's will work. But I don't know. I hope I can send these tires back and get a refund or something. I bought them online, and have a 4050 mounting machine.

 

[WRXracer]

yeah

I had 275s on my stock rims.. they worked fine..

 

[Satan]

ive been running 275-40-17 on my stock 2000 gt wheels for 3 years now. Ive never had a problem at all, and have run a few sets of different brands. People will tell you it wont work, but for me, so far, so good. I say go for it since you already have them.

 

[keepsbreakin]

I am still debating. Somebody just placed heavy doubt in my mind at Firestone. Don't know what to do. Think I might mount one just to see.

 

[keepsbreakin]

Might as well. I have them already. You're right about that. If it works for most, than hopefully it will work for me.

 

[WRXracer]

ok

everyone I know runs 275s in the back.. dont listen to firestone look at that they did to the explorers.. ..

 

[DarkHorse164]

Might as well. I have them already. You're right about that. If it works for most, than hopefully it will work for me.

Tire pressure will play a role in oversized tires on a narrower-than-recommended wheel, too. The tire will wear fastest in the center if oversized and not inflated properly. Since several members and friends of yours are having success with this combo, determine their inflation rates and adjust yours accordingly. Don't know if tire brand matters, but I've gove this route in the past on a sport truck, and found that BFGoodrich tires lasted as if they were the "correct" size. Nittos, well, I got about 3000 miles before they were in need of replacing. That was due solely to over inflation. I can't remember which model tires I used for each brand, though. If you stay with stock wheels (17x8's, you can go 255/45's comfortably, and possibly a 265 berfore pressing the premature-wear issue. Good Luck!

 

[68 & 00 GT]

I have 275 /40 R 17's on 8.5 in rim. Fits fine. barely bulges on the outside w/ proper tire pressure. You'll be fine. He was just being overly cautious I guess. I had Discount Tire mount mine that way several times, and they never said anything. Those customer probably left out that they leave rubber all over your town - Otherwise why would they be wanting wider tires if they weren't into the cars ?

 

[ForPointSex]

I have kumho 712's all around on the stock 8" rim for the last year with no problems and no un-even wear marks. With the bulge, my rims don't get scratched from curbs any more.