Tire Questions

[steve04]

Ok ive been looking over the forums and ive seen alotta wheel n tire info but havent seen enough to answer my questions. I'm new to the wheel n tire thing and would hate to waste money on tires that dont fit. All this backspacing and offset etc. for wheels is like a foreign language to me.

I have an 85' Grand Prix

I just got some Centerline wheels that are 15x8.5. I'm looking at running
Front: 235/60/15
Rear: 255/60/15

Would this work ok?
Do you think I could run 275 in the rear without a problem or would 255 be better?
Do you think 70 would be to tall for the rear?

Any info would be greatly appreciated. Thanks.

Steve

 

[Blake442]

235/60 and 255/60 are perfect for a G-body.

Go with a 4" backspace on the wheels if you can, they'll fit like a glove.

70's are a bit tall, and can catch the wheel wells...

 

[dogsht]

With an 15x8.5" rim you can run 275/60/15s or 295/50/15s. The 295s may require an inner fender lip roll even with good backspacing and or an air bag in your coil(s). The air bag thing is a great idea anyway especially with a posi as you can use it to pre load the suspension for the best traction. 255/60/15 also look great on a g-body and are the best size for a 15x7.

 

[steve04]

Thank you both for your help. I appreciate it.

 

[ilduce]

Ok ive been looking over the forums and ive seen alotta wheel n tire info but havent seen enough to answer my questions. I'm new to the wheel n tire thing and would hate to waste money on tires that dont fit. All this backspacing and offset etc. for wheels is like a foreign language to me.

I have an 85' Grand Prix

I just got some Centerline wheels that are 15x8.5. I'm looking at running
Front: 235/60/15
Rear: 255/60/15

Would this work ok?
Do you think I could run 275 in the rear without a problem or would 255 be better?
Do you think 70 would be to tall for the rear?

Any info would be greatly appreciated. Thanks.

Steve

What size rims and tires are on your car now? I have an 85 GP that had 14s with stock size 195/75s. No Pontiac 15s that I tried would fit on my GP. I managed to do 14-inch Rallye IIs after trial and error. Only two can go on the front (with discs) because the other two rub the tie rod ends due to backspacing problems (so they're on the back). Throw your aftermarkets on and make sure they fit before you buy tires if you have 14s on. If your GP came with 15s, you'll be in better shape than I was to start. By the way - if you had 14s stock, the only other tire size beside 195/75 that will work perfectly with your speedometer is 225/60 (in a 14-inch tire).

 

[steve04]

I have 15x7 wheels on now with 205/60s. They fit fine. I have test fitted the 15 x 8 1/2 Centerlines I bought and they seem to fit fine.