Tires

The tires all need to be within a certain range of diameter to avoid wear on the system. Now if you punctured one and couldn't repair it, you could buy one new tire and have them shave it down to match. It doesn't make sense to do this in your situation.

One other point- it seems counterintuitive but the better tires should go on the back. It helps for maintaining control in manuevering. You can check other sources to confirm. I think tirerack.com has good explanation of the situation.

 

Thanks MBS...

I went to Tire Rack as you suggested.

Great tech article on AWD and tires swaps.

Skip

 

Can you post article?

 

Article Link: Changing AWD Tires

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=18

 

AWD, FWD or RWD, regardless of which wheels do the driving, changing the tires 2 at a time is a bad habit that you don't want to ever start! With proper care & rotation, you should be able to wear the full set down evenly.

 

If you want maximum safety, you'll want 4 tires with the exact same characteristics. You can get by with changing tires in pairs [one axle at a time] on a FWD or RWD vehicle, I've done it many times. I try to avoid it now. A couple hundred bucks over ~3yrs is nothing.

Joel

 

I know Audi's Quattro system was extremely picky about having tires that are worn differently on the car. I'm sure GM's AWD system cares but probably not as much.

I agree your tires should wear out evenly with proper rotation.

 

Pairs

Here's the other article on which axle should get the new tires if only one pair is replaced: http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=52&currentpage=18

 

I have an 06 Envoy denali. I blew out a tire and was told the that side wall is gone and cannot be fixed. Les Shawab told me that I needed to by 4 new tires because the tread needs to be the same. The current tires were brand new when i purchased the vehicle last July. I've put close to 7000 miles on them since purchased. Do I really need to buy 4 new tires. It's not AWD.

 

You may not be AWD, but you still have 4x4 capability, and that is when having same size tires is important. And if you have Stabilitrak or traction control, a tire of a different size can cause issues with those systems.

I believe a difference of 1/4" in diameter is the outer limit. You have 2 options, try to find the exact same tire as the other 3 or try to find one that is within 1/4" in diameter.

 

Subaru specifies that the new tire must be within 2/32" tread different, at most. Most car tires come as 10/32", a few as 9/32". Some light truck tires that the Trailblazer might use comes in a 12/32" tread.

I find it handy to have a tire tread gauge. I've had one for several years. Very inexpensive.

If I have an flat that cannot be repaired, I calculate mathematically what it the better thing to do, buy 1 tire, buy 4 tires, or shave the 1 new tire. With 10/32" tires, it's easy:

other tires 10/32", buy 1 tire
other tires 4/32", buy 4 tires because they are worn out, too
other tires 9/32", buy 1 tire
other tires 8/32", buy 1 tire (but could buy 4)
other tires 6 or 7/32", this is where I would have the new tire shaved unless the old tires were old and I drove very little miles annually.
other tires 5/32", buy 4 new tires

With 6/32", if I buy 4 new tires, I am throwing about 6/32" of tire wear (6 to 4/32 is 2/32", 2/32" x 3 = 6/32")
With 6/32", if I shave the one new tire, I am throwing away 4/32" of tire wear from 1 tire.

 

You can have six different BRANDS of tires all listed as the same identical size and still have all six measure differently. Trying to get that 1/4" difference will drive you insane.