Replacing one tire or all four?

Had a tire blow on my 2015 5.7L Tundra the other day. Some folks (including one that used to own and run a tire shop) are telling me that I need to replace all 4 tires on my truck, because the new tire will have a different tread depth which will cause that wheel to roll at a different RPM than the other three. What is everyone's opinion on this? I'm not sure if the differential on the rear axle is open, limited slip, or locked, and I assume that would make a difference as to the answer to the question.

 

Depends on mileage on the tires.

 

^^^^^
If tires are low mileage, just get the one. If the tire is high mileage and tire is on the rear, get 2, unless it is 4wd then I would probably get 4.

 

Welcome to the forum.
I think you wanted to buy 4 new tires anyway and just wanted us to talk you into it...

I would agree with the posts above.

 

Replace with 4

 

LOL just the opposite actually. The tires aren't very old, and the difference in tread depth wouldn't be very much. The issue for me is that I don't know how to validate the claim that two tires with different tread thickness can beat up a differential. The more I think about it, it doesn't make sense that a differential couldn't handle the difference in RPMs between the two tires. Roads aren't always level, tires often have different pressures in them, and every time you turn a corner one tire is going to rotate way more than the other....so if those things aren't blowing differentials up, would the tread depth thing really be that big a deal?

 

never done it, but i've heard that tire shops can actually shave down the tread depth on the one new tire to match the others to eliminate this problem

 

How many miles and what tires are they?

 

I have one tire with 17000 miles on it and the other three are close to the wear bars (mileage unk) and due to be replaced. I have had no issues or drivability problems. All four are Michelin LTX M/S2

 

We need more info to be objective. Including age, brand, mileage and tread depth of current tires to make a reasonable recommendation.
I changed all my wife’s awd pilot’s tires after a “blow out” with 13k miles on them. I also did not like the original tires, and it was an awd. Either 4wd or 2wd will be more compliant with differences in diameter.

 

The difference is all those things you mentioned are variable. Replacing one tire with different diameter is constant.
That said, if the tires only have a few thousand miles just replace the one. If they have 10K+ on them replace all four if 4WD.
There are more systems at play than just the mechanicals. Your VSC, Speed Sensor and others depend on all tires being close to the same diameter.
Your call though. What do I know...

 

Maybe I missed how many miles on the good three?

What I’d probably do (again, what’s the mileage?), is buy a new tire and put it on the front with your new, never used, full-size spare. Rotate the other (good, nearly new-?) out to use as a spare.

 

1 tire. Tundras ride like shit anyway I doubt if you'll notice.

 

The OP could put the new on the right rear, and shave it down himself with a few smoky tire fires.

 

If it did it would only be when running in 4wd right? And if you're in 4wd it should be in conditions where it's slippery and a little slip is already expected so it wouldn't matter.

The rear differential already lets the left and right side tires turn at different speeds so it wouldn't matter if one is slightly larger than the other.

I say just buy one tire and be done with it unless the other 3 are almost at end of service life.

 

Almost all 4wd trucks have a limited slip differential. It's definitely not a locked. If you try to go around a turn on pavement in a truck with a locked differential, you'll know (It won't want to turn...at all).

 

I did exactly this. Had a similar scenario a while back and ended up only replacing the one tire that had a blowout. Swapped the full size unused spare tire onto one of the other wheels and put the used tire on the spare wheel. BTW - some tire shops will not shave a tire over a certain size, so this was the easiest and cheapest vs. replacing all 4 tires.

 

Do you mean it depends on the wear or diameter? Mileage alone shouldn’t be a factor, but a tire with more mileage is likely to be smaller in diameter. Is that wha you meant?

 

I did some math. It looks like at 4/32” wear on one 33” tire, the rotational speed would be 0.04 revolutions per second more on the worn tire.

 

replace all 4, use the best one of the old set as your spare.