Need Advice From the Tundra Gurus - Spare Tire Swap

I hit a massive pothole today and thankfully made it home as the front passenger tire lost air. I started to put the spare on and noticed it was a different size. The spare is a 255/70R18. The regular tires on the truck are 275/55R20. The tire shop is a few miles away. Should I: 1) inflate the tire losing air and hope it holds air until I get to the shop, or 2) put on the spare and hope the size difference does not screw up the 4x4 system?

It is a stock 2020 SR5.

 

It's not going to hurt anything as long as you get it fixed soon.

The only trouble you will have is the speed sensors will register a different speed and may give you a warning light.

It will also make it difficult to engage 4wd. You may have to be stopped to fool the computer.

I wouldn't do shift on the fly to Or from 4wd. It will definitely make a loud thunk.

 

Difference in diameter is only like a tenth of an inch. You’ll be fine.

 

You Tundra boys sure are great, thank you joonbug and koditten.