Doc's advice on tires

Subarus and other all-wheel drive (AWD) vehicles have a great reputation for being able to get through just about any type of weather by applying the engine's power to all four wheels while compensating for wheel spin. Given the complexity of most AWD systems, the common task of replacing tires can become difficult. Most dealerships and garages will state that in order to prevent damage to the transmission and differentials on the car, tires need to be replaced in full sets of four. By having all four tires at the same tread depth, power can be distributed evenly. This avoids the strain of shifting power to one pair of tires (per axle) or one individual tire when mixing old and new tires on the same axle. However, if the differentials or viscous couplings are forced to operate 100% of the time because of mismatched tires, they will experience excessive heat and unwarranted wear until they fail. To make sure your tires are working in unison, read "Matching Tires on Four-Wheel Drive and All-Wheel Drive Vehicles."

What if three of your tires are still in great shape and you only need to replace one? We can shave a replacement tire for you to the proper tread depth. For a cost of $25 to $35 per tire, our Indiana and Nevada distribution center can shave a brand new tire down to the desired tread depth to best match the damaged tire(s) wear. This keeps your costs down by replacing one tire instead of all four. Shaved tires will also better match the traction and handling qualities of the remaining worn tires. Before calling in your order, measure the damaged tire's tread depth in several places to get the best average and by combining that information with the exact tire size, brand and model, we can shave a single tire down and provide a near perfect match for the damaged tire. 

Bear in mind, that at 2/32nds of an inch of remaining tread depth the tire is considered completely worn out according to most states' laws. You should consider replacing your entire set of tires if wet roads are a concern and your tires' tread depth reaches approximately 4/32". Replacing your set when they reach approximately 6/32" of remaining tread depth is also recommended if you encounter snow-covered roads. To see if your tires are in need of replacement, take a look at "Measuring Tire Tread Depth with a Coin."