In our hands at the tail end of a rough winter around our Chicago offices, our STI had winter tires. STIs have 18-inch BBS alloy wheels and P245/40R18 summer tires, versus the WRX’s P234/45R17s.Our trained experts have years of wheel fitment experience and. Tire Rack makes it easy when you shop by vehicle. Wheels and Tires: 2016 Subaru WRX STI: WRX STI: Wheels: Size (in.) 18 x 8.5: Material: Aluminum-alloy wheels with dark gray finish: Tires: Size: 245/40 R18 97W : Type: Summer-performance tires: WRX STI Limited: Wheels: Size (in.) 18 x 8.5: Material: BBS® forged aluminum-alloy wheels with high-luster silver finish: Tires: Size: 245/40 R18 97W.This includes a turbocharged, higher horsepower, four cylinder engine and a stiffened, sport-tuned suspension system. The WRX designation incorporates rally racing-inspired design and engine performance. The Subaru WRX, or the Subaru World Rally eXperimental, is the high-performance edition of the Impreza. Important Notes Due to variations in wheel appearance based on size, bolt pattern, lip depth, etc., the wheel shown here may not accurately represent the design specifically for your vehicle.