Why do Subarus need all four tires replaced?
Your Subaru’s AWD system needs tires of uniform diameter and tread pattern to operate at peak performance. Subaru recommends replacing all four tires at once. However, if your remaining three tires are relatively new then you may be able to replace just one with the same brand, model, and size. Should You Replace All Four Tires on Your AWD Vehicle at the Same Time? In most cases, yes. All-wheel drive (AWD) systems are designed to work with four tires that closely match in size and tread depth. Replacing only two tires can create differences in wheel speed that affect how the system distributes power.