I have the 20" Michelins tires and my spare is a 18" Goodyear. Anyone else have a mismatched spare?

 

That is the way they are listed in the order guide. Ford has used a less expensive tire on a steel wheel for years as the spare. The diameter of the two is within an inch and more than adequate to drive on long enough until you get it repaired or replaced.

 

I was suprised to see they now also have a tether.

 

I have owned 5 Super Duty trucks including this 2017. All of them had a spare with a steel rim, but every single one of them had a matching tire in size and brand. Maybe yours was an early build with a tire shortage?

 

My 2007 ccsb with 20" rims had a steel 18" spare that was about 1" smaller in size same with my 2014 regular cab with 20"
If you look at your door tag it will even show the 18" spare

 

I've never had a truck with 20" rims...so perhaps this only applies to trucks with 20" rims.

Maybe a 20" tire won't fit in the space allocated for the spare? But the 18" 275x70x18 is only about 1" in diameter smaller than the 275x65x20 size...which translates to only needing an extra 1/2" on all sides. Hmm.

Brands have always matched - I've had Continentals and Michelins.

 

There's room under there for a full size spare i think it's the bean counters and having to produce a 20" steel rim

 

The '01 was an early build, Oct2000. The tires were the Michelin M+S but the spare was a GoodYear AT. Both are 16".

Order guide re: spare tires

 

I agree. I have fit a 37x13.50x20 tire under my truck in the stock spare location and I also have a factory 18" spare. There is loads of room around the factory spare.

 

I thought this was weird to have 20's with an 18 spare on my truck. You would think a truck this expensive would have a matched spare.

Only thing I can find to complain about with this truck!

 

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My 19 F250 Limited came with an stock type 18" steel rim with get this, a Goodyear Kevlar run flat spare, not a Michelin as supplied on the truck itself. Have it for sale if anyone needs a spare. Have since purchased a matching rim and spare the same as I'm running (Nitto Ridge Grapplers) so I have no use for the OEM spare.

 

The wheel size doesn't have anything to do with the diameter of the tire.

 

The 18in spare isn't new to Ford or other manufacturers. I've got the 18in spare and was noted in their documentation when I placed my order back in 2017, My previous GMC was the same way.