A tire question

[jat]

Hi, I am new here. I found this site looking for an answer about my tires.
I had a flat a couple weeks back, it was unrepairable. I was told at a new/used tire place, that I had to buy all four tires, unless I could find an exact match. Of course, they didn't have one, and I was driving on the spare.
The guy said I could ruin my transmission if all my tires weren't exactly the same. I went elsewhere, where he said I should be fine with the tire he had. It was the same size and make, tread almost the same, but it was for a heavier duty truck. Is that really a possible problem, because now there actually is a funny grinding/slipping or some such sound. Please advise. I love my truck! Thanks, jat.

 

[Blee1099]

As long as the tires are the same size there shouldn't be any adverse effects from it. The truck may ride different not having a matching tire but that should be minimal.

 

[jat]

Thanks...

 

[Wade Lippman]

They encourage you to have 4 identical tires. That way they have the same traction, so you don't get fishtailing; and they all rotate the same. As long as the difference isn't too extreme it doesn't matter much.
My wife's AWD Grand Caravan has a space saver spare. You can't get much more different than that, and the van drives reasonable well on it. (she blew a rear tire out on a curb last month; darned if I know how...)

That's a good point (that she has AWD)... The difference is more important in 4WD on firm pavement because the tires are prevented from rotating differently, but in 2wd or 4wd/snow it should be fine.