Does My Spare "need" to be the same size as my other tires?

I just ordered a set of tires, stepped up to 265/70-17. Only about one inch bigger than stock diameter. I don't really want to buy a full size spare and I don't think I need one. If I ever do have to run the mis-sized spare, I figure I will put it on the back and then not use 4WD. Does that sound like a bad idea?

 

Think about it, most spares are much smaller then a full size tire. I'd think if u don't driver very far you'd be fine. Just my 2 cents

 

do you have a LSD? If so you need to match the sizes but otherwise you should be fine.

 

^^^
This. If you have a mechanical LSD you need the right size spare. Running one the wrong size on the axle with the LSD will wear out your LSD clutches.

 

If you're just limping home and have an open diff on whatever axle gets the spare, you'll be fine.

Fullsize spare is nice due to preserving the ability to use 4wd, although technically you can do that with an offsize spare as well.

 

If you need it, put it on the *front* and then don't use 4wd. That'll keep your differential from working too hard.