Hi,

I’m wondering if anyone has tried to replace their spare to match their other tires so that there are no limitations if you have to replace a spare mid trip and can’t repair it right away. We will be towing a trailer on some trips. I don’t go true off-reading, but do travel down sometimes quite rough forest service roads. There is, for instance, a campground about 30 miles down somewhat rough forest service roads that we sometimes visit.

My main tires are 275/60R20 115T
My spare is 265/70R18 116T

Would a larger tire fit? Are the wheel size usually the same (my truck has upgraded 20” wheels, so that may be an issue)?

 

Your spare is about the same size as the 4 on the vehicle. The spare is 0.3" smaller based on the math. plus/minus depending on tread depth and manufacturer.

4x4 engagement could be harsh if you needed to use 4x4 while on the spare, otherwise it's all good.

I think all the F150's are coming with the 18" spare, regardless of wheel size on the vehicle. Because the tire size is all that matters, not the wheel size.

The 70 series spare vs the 60 series vehicle tire makes up the difference.

 

Oh that’s good to know thanks. I am relatively ignorant about tire sizing and this is our first 4x4 vehicle. We don’t do true off-roading, though we definitely go down rough forest service roads. And we do tow a trailer on longer trips, and sometimes down long dirt roads as well. But your comments put me at ease that we’d be fine.

 

My truck originally came with Bridgestone tires on it and the spare is Goodyear! LOL!