I have (2) new snow tires and (2) used snow tires. Both are the same size and brand. P195/60R14 Blizzak WS-50's. The new tire tread depth is 12/32, the used tires are 7/32.

Is this difference too great to run the new on the front and the used on the rear. I have a 1989 manual AWD XT6.

What is the max differance allowed between front and rear on the old school AWD systems? What is it on the new AWD systems?

 

Should I just buy two new tires?

Theoretically, you should have all four tires be EXACTLY the same diameter. IN the snow and Ice, that won't matter so much because the ice and snow will probably introduce enough slippage to overcome any binding that may occur. That is NOT the case on pavement, though. If you have a Full time 4wd XT6, though, you have an open differential in the middle. It will tolerate some of that sort of abuse, but personally, I wouldn't push it. I'd get two new tires and sell the used ones to someone to help offset the cost.

Thanks. Since I'm traveling 3K for X-mass I don't want to push it. Most of the time I figure the pavement will be dry. Getting two new tires.