Opti-Lube XPD has become the standard for fuel system protection in common rail VW TDIs. It offers outstanding lubrication, helps burn fuel more completely, and reducing harmful engine deposits and oil contamination. It shows a 42% wear reduction in the ASTM D-5001 Wear test, and can show up to a 5% improvement in fuel economy.
One quart bottle. Use 1/4 to 1/2 oz per gallon of fuel.