285/75/16 with 275/65/18 spare (2 Viewers)

[Vagabond Nate]

Hello all. I have an 03 LX with 275/65/18 Michelin Defender LTX tires. I'm picking some 16" LC wheels with lightly used 285/75/16 KO2's but there are just 4 of them. I know that there's a decent size difference but would this be enough to damage the differential (or anything else) if I need to run the spare to get to a shop? I plan on doing some light off-roading fairly soon and I will be pretty far from a shop at times.
This is kind of a temporary test to see how I like running these larger, heavier All Terrains without breaking the bank. I will pick up a 16" spare LC wheel and matching tire if I like this setup when I buy the next set of new tires.

 

[zipdoa]

ChatGPT to the rescue.

A ~2.2% difference (from mixing 275/65R18 with 285/75R16) is within what the center diff can technically handle short-term — but it still causes continuous slip, and will generate heat and wear over time.

Logic dictates that you should get a matching spare - at the least buy a used tire of the same size circumference.

 

[Vagabond Nate]

ChatGPT to the rescue.

A ~2.2% difference (from mixing 275/65R18 with 285/75R16) is within what the center diff can technically handle short-term — but it still causes continuous slip, and will generate heat and wear over time.

Logic dictates that you should get a matching spare - at the least buy a used tire of the same size circumference.

Thanks for the info. I definitely will eventually get a matching spare but it doesn't make financial sense at this stage if it's something the diff can deal with for the distance it takes me to get to a tire shop. I've been looking for a single wheel and/or a used matching tire in my area without success so far. Since KO2's have been discontinued, I'd rather not spend the money on a new tire that doesn't match.

 

[ScotyDosentKnow]

Thanks for the info. I definitely will eventually get a matching spare but it doesn't make financial sense at this stage if it's something the diff can deal with for the distance it takes me to get to a tire shop. I've been looking for a single wheel and/or a used matching tire in my area without success so far. Since KO2's have been discontinued, I'd rather not spend the money on a new tire that doesn't match.

If it were me I would buy a good used 265/70R18 to put on the spare. That would be 0.6% difference in diameter and you could probably get away with driving a pretty long distance to get to a tire store or just get home etc. Im not sure about rigs with AHC but I have a 33" spare under the truck. Its tight but fits fine.

This website will let you compare tire sizes and shows the difference between the two:

Tire Size Comparison

Tire size comparison the easy way. Use our tire size comparison calculator to compare diameter, width, sidewall, circumference and revolutions per mile.

tiresize.com