When tires are replaced in pairs in situations like these, the new tires should always be installed on the rear axle and the partially worn tires moved to the front. The reason is because new tires on the rear axle help the driver more easily maintain control on wet roads since deeper treaded tires are better at resisting hydroplaning.

Some tire stores insist on installing two new tires on the rear wheels of vehicles when the fronts are worn, and moving the old rear tires to the front--much to the dismay of many customers who want the new tires on the front. So, who's right?

Actually, I agree with the stores, as do the tire companies. Here's why: In dry, clear weather it really doesn't make much difference. But if the road is wet, the new, full-treaded tires are less likely to lose traction than the partly worn ones. If you're hauling ants down the road and come to a wet curve, the full-treaded tires on the rear will stay behind you, where they belong.

If the rear tires have less tread, there's a greater chance that they will slip, putting your rear bumper into the ditch. Okay, if the front tires skid, there's the chance you might go off the road, too--but at least it'll be headfirst, where your seatbelts and airbags offer more protection.