2006 fx4, looking to go to larger tires 295/60r20.

I would have liked to get a cheap tire and mount on a wheel to keep under the truck as a spare. Looks like it won't fit, am I right on this?

Also, let's say I do get a flat on my new tires, I COULD use the smaller diameter spare I guess but it can't be good for the differential........

 

If you use a different size spare, I could be wrong on this, but you need to put it on the front so the rear tires are always matching in diameter. Then as long as your in 2wd the rear diff should be fine. Now extended driving can cause the other tire in the front to wear abnormally so you need to keep the driving to a minimum.

 

Hmmmm. If that is right then I'm good with the stock spare, I'll just make sure the spare is on the front.

 

Pizzaman711 is 100% correctbut you need to put it on the front so the rear tires are always matching in diameter. little extra work when ya have a flat!

 

I'd suggest finding a used tire that is the same height as your tires and use it as a spare.