Originally Posted by BCRAM
I was crawling under my truck today and noticed that the spare tire is 17" whereas the truck has factory 20" tires.
The question I have: Is the correct? I know that many vehicles come with a smaller/compact spare and normally would not think 2x about using it. However my truck has a limited slip rear end and I would be very hesitant to out a smaller diameter tire on as I would be worried about damage to the LS due to the tire size difference.
That said, due to the factory trailer hitch, there is not much room if any for a bigger tire under there as it looks like the tire would not fit...
Are my concerns justified?
The rim diameter is irrelevant, it's the tire's diameter that matters. Your spare is relatively close in diameter to your 20's, and LSD's are forgiving enough for minor differences anyway. It's not like you have a locker or spool. You are completely safe to run your spare.