Slick 50 Recharged High Mileage Engine Treatment propriety ZDDP formulation is built from a base of fully formulated multi-grade motor oil that meets ILSAC GF5 motor oil specifications for high mileage engines. Unlike some oil additives Slick 50 will not dilute the additives already in your motor oil.This product is dispensed in 10W-30 which is a multi-grade oil but is fully compatible with all multi grade motor oils and mono grade oils. It is fully compatible with all conventional, semi-synthetic and full synthetic oil types.