Q. Can I replace just my front two tires or my rear two tires, or do I need to replace all four tires at the same time?
A. Some manufacturers recommend replacing all four tires at the same time, especially in four-wheel or all-wheel drive vehicles. Since the computers in these cars monitor the speed at which each wheel is turning, even a slight difference in circumference due to tire wear can send faulty information to the computer. That faulty information can result in undue wear on the transmission and associated hardware. Translation - expensive repairs.
Some manufacturers will even void your warranty if all four tires don’t match in circumference, wear or tread design. On cars without all-wheel drive, four-wheel drive, and new-fangled stability control, it may be practical to replace either the front or rear tires but you should check with your dealer.
If you have a front-wheel or rear-wheel drive car, you can probably get away with buying just two new tires. Some people think you should put the tires on the wheels that the engine is powering. But put them on the rear, even in front-wheel drive cars. If your front wheels lose traction, you feel it quickly and can slow down and adjust your driving. If your rear wheels lose traction, by the time you’ve felt it, it’s usually too late. Better grip in back is the safer choice, and helps keep your rear-end behind you, where it belongs.