These are the same premium pistons we use in our winning race and high performance street engines around the world. We feel that these are the best pistons for your high performance or racing engine. Working closely with CP, these pistons meet our most stringent expectations and are the finest available, anywhere. We stock a variety of compression ratios and can also supply you with custom piston applications quickly. Many pistons look alike, however; our CP Pistons use spot on clearances, specification, dimensions, and metallurgy that are specifically engineered to perfect compatibility with each BMW application and engine technology.