My car has different diameter tires in the rear than the front and I want to have only 1 spare. It also has posi. If I had a flat and ran a smaller tire on the rear for a spare would that cause a problem with the posi? I know it makes a difference on 4-wheel drives so just want to be sure.

Thanks and have a good holiday!

Mark 66SS

Yes ,it will cause some wear on the clutches but as it's temporary ,it'll survive.
Think I'd carry a spare the diameter of the rear ,but not necessarily the width of the running tire.

yeah, i need to buy a spare also and i'm going to match the rear size. If for some strange reason i had to put it on the front it would throw off the alignment for sure being a different size, but it would be temporary. My tires aren't that huge of a difference anyway. 235/60/14 up front and a 265/50/15 in back. Heights are less than half an inch apart.

My sons Jeep Cheerokee's posi had the wrong tires put on by wal-mart. He was coming home from pennsicola and 75 miles into trip the rear blowed the plastic plug out and exploded into flames. Destroyed the rear and $3800 in damages. He had driven short trips for 2 months around town with no problems noticed. If you need to travel very far I would say no way considering what I saw.

Running mismatched tires on the rear with a limited slip (posi) rear end will wear the clutches and overheat the oil. If it was for a very short distance at slow speed then it would be all right.