All-wheel drive vehicles offer advantages for traction especially in wet and snowy conditions over traditional two-wheel drive models. Unfortunately, since all four wheels are connected, a single blow out or non-repairable puncture can become an expensive proposition. When you install a new full tread depth tire with other tires that have less than the new, an overall diameter difference occurs. Different diameters result in different spin rates. A shorter tire must rotate more times to go the same distance as a taller tire. You can do an experiment to demonstrate this with a quarter and a penny. When rolling these two coins, you'll see the penny requires more rotations to keep up with the quarter. This variance in rotation speeds will result in resistance in the drive line and will generate heat which can lead to premature failure of major drive line components.
Is there an alternative to replacing all four tires? Absolutely, we offer a tire shaving service where we shave your new tire to match the tread depth of your remaining three tires. The cost of our tire shaving service ranges between $25 and $35 per tire and is significantly less than the cost of replacing the other tires on your vehicle that still have lots of mileage left in them.
For more information on this service, read "Matching Tires on Four-Wheel Drive and All-Wheel Drive Vehicles."