Add to regular or synthetic oil. Reduces engine oil temperature up to 57 degrees. Cools radiator water up to 7 degrees. Doubles life of lubricated parts. Dramatically reduces engine noise. Cools turbo up to 25 degrees. A must for all hard working and constant running diesels. Can increase fuel mileage. NOTE: Shipping to Continental United States Only. No P.O. Boxes. Ground Ship Only.