Tire Wear / Mileage

[thom1301]

I have a nearly stock (intake, recirc BOV, boost controller) '96 AWD Talon. I just checked the tires, and rears are worn down almost to the wear bars, and the fronts look almost new. This is after about 25,000 miles on BFG Traction TAs (all season) in 215/55/16. Any ideas on why this would be? The rear wear is pretty even, with just a little more wear on the outsides of the tires. I do 95% highway driving, and still only get 22-23 mpg. Any thoughts?