Engine Performance Restore EPR is formulated to assist in dissolving and removing hard-to-clean deposits from piston rings in as little as 10 minutes. It is designed for use in gasoline and diesel engines as part of routine maintenance. By helping clean micro passageways, it supports the hydraulic function of components such as valve train actuators and turbochargers. This product is used before an oil change to help remove deposits and contaminants. It is intended for professional use only and should not be used in engines with excessive sludge buildup.