Wynn's Hydraulic Valve Lifter Treatment 325ml cleans away internal engine deposits that create noise and reduce efficiency. It restores efficient working of hydraulic valve lifters, lubricates and releases sticking valves, and reduces valve train noise, restoring lost power. This treatment is 100% oil soluble and safe for use with catalytic converters and turbochargers. It is compatible with mineral and synthetic engine oils and suitable for regular and low SAPS applications. Add the entire contents to the engine oil (up to 6 liters of engine oil) at each oil change or more frequently if required. Add contents to the engine oil when the engine is warm and operate the vehicle normally.