I have a novice tire question.
If I have two different size tires what size would I use as a spare?

P215/65R15 front
P255/60R15 rear

Thanks, Guy

 

The 215/65R15 will take up less space in the trunk, an inch difference between the two. I have 205/75R14 and 215/75R14 on my 70S so I just carry an extra 215/75R14 in the trunk. With my 88 CSC, I have 205/70R14 on the front and I am putting 225/70R14 tires on the back, so I will carry a 205/70R14 and a 215/75R14 since I have a couple extra.

 

Thanks for the prompt follow up.

 

The question should be, can I run 2 different size tires on a posi rear end over a long distance without doing damage. If you have a posi, the spare should be the same size as the rear tires.

 

Actually, the posi (OK, Anti-Spin... ) only cares about tire diameter, not width. The 255 might be a clearance problem at the front. Consider getting a spare that is the same diameter as the 255/60, but narrower. You want a tire with a 27" OD. If you can find a 235/65-15, that would be perfect. 205/75-15 would be close (27.11" diameter vs. 27.05").

 

That's what I meant as there was 1.04 difference in diameter between the fronts and back.

 

Read my response again. Use a spare that matches the diameter of the REAR tires (to avoid posi problems) but with the width of the FRONT tires (to avoid rubbing problems. Yeah, the different diameters in the front may cause it to pull slightly, but it won't damage anything and you're only driving to the next exit off the freeway.