Alright, I noticed a bulge on one of my front tires, definitely not driving another mile on that one. However, my tires are 235/85/16 and the spare is still the stock 215/85's. Am I safe running one smaller tire on one side in front? I've heard it's bad for anti-spin differentials in back to run different size tires, will it mess anything up front? It is 4x4 but i'm obviously not intending on putting it in 4 wheel drive while driving like this...the reason I'm wondering is I have already planned on buying a new set (this set has close to 75k miles...) next week but have to drive about 3 hours this weekend to my parents house and I dont want to screw up the 4x4 system in the process Any advice? Thanks in advance..

 

I am not a 100% about this but here goes. I don't think short term driving with mismatched tires as close as yours will hurt. The differental in the front is designed to compensate for the mismatch that a turning situation creates (inside tire has to rotate less than outside to cover difference in turning radius) I certainly wouldn't do it long term or in 4wd which doesn't allow slippage front to rear. Hope this helps.<br>Tim<br>Heck, FWD cars have been doing it with donut spares for years

 

you will not hurt anything as long as one tire on the front is the same as the rear, unless you have a posi unit in the front differentual. you can run 4 wheel drive. the spider gears in the diff will take care of the tire size.i wouldnt want to do it long term. a 20 to 30 mile trip in 4/4 would not hurt a thing. this may start an argument but i have been in the business for 42 years i think i know what i am talking about.

 

Sounds good, thanks guys. I've driven it a few miles tonight and it seems to act normal. Out of curiousity I measured the diameter of each of the fronts and they were within an inch of each other anyways (the spare is almost brand new and like i said the 235's have 75k miles) so i'm not too worried. Thanks again