When it comes to cooling, Stewart is the final word in high performance pumps. The ultimate in BMW cooling with a limited lifetime warranty! This high performance water pump is a direct replacement pump, accepts the factory fan clutch. The front is stock appearing for a clean look, and the back of the pump is all business! Up to 20% increase of water flow over stock pump Twice as efficient as factory pump Much less parasitic drag than other pumps Racing or Stock Factory Replacement applications Stainless Steel Impeller Heavy duty Larger bearing High quality water seal (Carbon Graphite) Limited lifetime warranty from Stewart