Dear Tom and Ray:

The other day, I went to purchase two tires for my Dodge Intrepid. I wanted to replace the front pair and move my old front tires to the back. That way, I'd get good tread for the snow in the winter. The local tire store told me that due to insurance regulations, when a customer buys just one pair of tires, they MUST go on the rear. They say the tire manufacturers advise the same thing. I argued back at him, and said that because my car is front-wheel drive, I need good tread on the front tires more than on the rear. "Well," he replied, "then you'll have to buy four new tires." Is this true? I think he just wants to sell me four tires instead of two.

-- Chester

TOM: Of course he does, Chester. But he's also technically correct.

RAY: Tire manufacturers and safety people now recommend that your "better" set of tires go on the back, even if you have a front-wheel-drive car.

TOM: It does sound crazy at first. It also sounds suspicious, because it provides a highly convenient argument for selling two extra tires. When we first heard about this policy, we said: "That's a fraud! It's a blatant rip-off! Let's implement it at the garage immediately!"

RAY: But the logic is actually sound. Putting tires with brand-new tread on the front certainly would help you get started in the snow. But having worn-out tires on the rear could cause the rear end to slide out when you try to turn or stop.

TOM: And since you can steer the front wheels, you have a better chance of maintaining control of the car if the front wheels slide than if the rear wheels slide. Once the back end starts to slide, it's a lot harder to control the car, and an accident is often the result.

RAY: Of course, having four good tires is best. But my guess is that this policy came from the tire companies' legal departments, not their sales departments -- despite the conclusion it leads to. Although I'm sure the policy has been warmly embraced by the sales staff, too.