Spare tire

[Cyrusblack]

I seem to remember someone saying that the spare tire was different than our Goodyear Wrangler tires so I went outside to check. The first thing I checked was the underside chassy for rust and there was zero. Then I checked the spare. Although it was a brand new spare it was not a Goodyear and the size was smaller than our 255/65R18’s. ?

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[CACTUSGREYFX4]

Now I need to crawl under mine . Today was tint, tomorrow tonneau cover maybe after I get home from that.

 

[gForceDude]

I seem to remember someone saying that the spare tire was different than our Goodyear Wrangler tires so I went outside to check. The first thing I checked was the underside chassy for rust and there was zero. Then I checked the spare. Although it was a brand new spare it was not a Goodyear and the size was smaller than our 255/65R18’s. ?

Stock Tire size 255/65 R18 is virtually identical in diameter to your Spare Tire size 235/80 R16.
Compare them here:
https://tiresize.com/comparison/

Diameter is the important number here.

Strangely, my Spare is 255/70 R17 (which is also nearly identical in diameter to the Stock Tire size).

 

[Cyrusblack]

Stock Tire size 255/65 R18 is virtually identical in diameter to your Spare Tire size 235/80 R16.
Compare them here:
https://tiresize.com/comparison/

Diameter is the important number here.

Strangely, my Spare is 255/70 R17 (which is also nearly identical in diameter to the Stock Tire size).

So you have 18’s all around and they gave you a 17” spare?

 

[gForceDude]

So you have 18’s all around and they gave you a 17” spare?

Wheels, yes.
But the Spare is a taller tire on the 17" wheel, and so it is the same diameter as the stock tire on the 18" wheel.
The diameter is the important number here. Wheel size makes no difference if the overall diameter is the same.
Compare them here:
https://tiresize.com/comparison/

 

[jedadiah]

I wonder if the FX4s have an more off-road capable spare on a 17" instead of the 16" street tire. My truck has 18s, but I'm a 4x2, so as long as the diameter is right, I'm fine. I didn't buy an off-road truck where I'd expect an off-road spare.

 

[Cyrusblack]

I wonder if the FX4s have an more off-road capable spare on a 17" instead of the 16" street tire. My truck has 18s, but I'm a 4x2, so as long as the diameter is right, I'm fine. I didn't buy an off-road truck where I'd expect an off-road spare.

I’m 4x2 as well. Never going off the pavement. . . On purpose ?

 

[Elfman]

Resurrecting this a bit to ask a question. I have a '24 Lariat FX4, with 255/65/18 on the truck and a 255/70/17 as the spare. But sounds like some of you have 16" spares. Wonder why the difference. Do 16" not fit on a Lariat, or maybe this is 4x4 vs 4x2?

 

[dard6555]

Look at the tire placard in the door for the correct size of spare. My Lariat came with a 16inch spare, the tire placard said 17 for spare and the 18s for the road wheels. Ford replaced it under warranty to make it match the placard. The tire placard is governed by FMVSS and has to match what comes with the truck.

 

[boraxman]

Had to look, mine came with a 5th BFG KO3 thankfully. Thinking of taking it and sticking it in the garage and carrying a plug kit and mini-compressor instead.

 

[Muffin1]

Another way of cost savings from Ford (short of deleting it) using a off brand.
I have never heard of that brand tire.

 

[Elfman]

Look at the tire placard in the door for the correct size of spare. My Lariat came with a 16inch spare, the tire placard said 17 for spare and the 18s for the road wheels. Ford replaced it under warranty to make it match the placard. The tire placard is governed by FMVSS and has to match what comes with the truck.

So if the placard says spare should be 17, does that mean a 16 won't fit (size of calipers or rotors)?

 

[dard6555]

So if the placard says spare should be 17, does that mean a 16 won't fit (size of calipers or rotors)?

The 16" wheel did fit over the calipers. I checked just to be sure. They are used as spares on the XL models. The Lariats should have 17 inch spares.

 

[Elfman]

The 16" wheel did fit over the calipers. I checked just to be sure. They are used as spares on the XL models. The Lariats should have 17 inch spares.

Yeah, I might want to put 16" wheels on my Lariat. The sizing on the placard seems to be a recommendation or statement of what is stock, but not an engineering design requirement of the truck, then. Am I right?

 

[dard6555]

Tire shops might not go smaller. Load rating has to be the same or higher as well.

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