From the factory your 2003 Chevrolet Impala is equipped with multiple pulleys. Pulleys are responsible for guiding and tensioning belts throughout the engine. The belts are connected to various engine accessories such as your water pump, your AC compressor, alternator, and power steering pump. High Performance Engine Pulleys are made from a lightweight material. Most pulleys are a direct replacement for your OE pulleys. Performance pulleys also add a nice clean polished look to your engine bay, no matter the finish you decide to go with. Sport Compact Warehouse is your premier source for performance engine pulleys. Reach out to one of our experienced representatives if you have any questions and we will help you make a more informative decision.