My 2004 V6 AWD with Goodyear 235/65-17 front and 255/60-17 rear needs new tires. Does anybody know the GMAC leasing rules are concerning tires when the car is turned in? Do they require the same brand and stock sizes? Is installing 4 235/65-17 or 4 255/60-17 acceptable? How much tread remaining is required? I have just another 6 mos. on this lease and frankly I want to spend as little as possible.