20" wheels
Posting Guru
Joined: Nov 2006
Posts: 1,154
Likes: 2
I picked up a 16" wheel that matched the ones on my truck from a boneyard, forget what it costed me though. I also got a 285/75 tire so at least the size matched the set on there now. When I replace these tires I will get five and have the spare be exactly the same as the rest, then do five wheel rotations.
If you have a LS diff you will need to have the overall diameter of the tires match for proper operation. I think they call it +2 sizing when you go to 2" bigger wheels but OA diameter stays the same. Maybe it's called -2 sizing when the spare wheel is 2" smaller? You know it's done for $$$ savings. I don't know why they can't at least offer a matching spare wheel when you order a vehicle...
If you have a LS diff you will need to have the overall diameter of the tires match for proper operation. I think they call it +2 sizing when you go to 2" bigger wheels but OA diameter stays the same. Maybe it's called -2 sizing when the spare wheel is 2" smaller? You know it's done for $$$ savings. I don't know why they can't at least offer a matching spare wheel when you order a vehicle...
Cargo Master
Joined: Aug 2005
Posts: 2,051
Likes: 1
From: Alberta, Canada
No they are not the same size, the factory 20" tires are about an inch larger in diameter. Ford does it because it is cheaper to put a smaller spare under there. If you do get a flat and have any distance to travel put the smaller spare on the front otherwise it will heat up your rear differential.
