wait....what??? how would that screw up AWD??? please explain.....ive never heard of this before...i could understand a huge tire difference (i.e. ???/50-55/?? vs ???/40-45/??) please explain.....

 

This is where I got lost.

 

So basically, the other tires have 1/32 less than the tire you are putting on there, unless they are really soft tires, and in that case, its 2/32 difference. If that will mess up your AWD system, you need a new car that doesn't suck.

 

Just put a new tire on it and don't worry about shaving it. The difference in height is negligable and won't affect your AWD.

 

You don't need to shave that.

I'd like to shave a flatspot out of mine, though.

 

Ok, here's the deal. Most of today's AWD systems(according to Subaru and Mitsubishi) use complex differential setups that require the tire/wheel setup to be close in circumference. If not, the tires rotate at different speeds, which(over VERY long periods of time) can cause premature gear wear, even failure. Now when I confronted Subaru about this, this handed me a pamphlet that does a decent job explaining it, and the service manager broke it down "Barney-style" for me as well. When I confronted Bridgestone/Firestone about this same issue, they said that the only time you need to worry is if there is a difference in tread depth GREATER than 3-4/32. If not, I would'nt worry about it. Cars nowadays wear out tires quicker than they can do damage to gearsets if the difference in tread depth is less than what I mentioned.

The only car as of late that I've been TOLD is any different is Subaru WRX STi models with the flexible DCCD(Driver Controlled Center Differential).

In all reality, it's one word against another. Make your own choice, and hit me up if it blows up.

 

nice....good to know as well...

 

Thanks. At first I was a little skeptical, and even more worried when I realized the WRX i had been sold from a local dealership had bald front tires and almost new rear ones. Oh well, it never broke on me, but the transmission definately went out after about a month of ownership. Meh, typical Subaru. lol

Correction:
I did hear of an AWD vehicle of some nature blowing out it's rear pumpkin in a situation like this, but honestly I can't remember what kind of car it was(I think it was a Saturn/GM SUV of some sort).

 

It's not a breakage issue, it's a premature wear issue. 3 or 4 32nds difference isn't going to hurt anything, and is fairly normal for an extended tire rotation interval. The DCCD has a clutch pack and will have accelerated wear, which isn't a problem with a WRX or 2.5i, etc. If you have pretty worn tires on one end and new tires on the other though, it's still not a great idea. It's not something that's going to break anything, just put a little more stress on everything.