Wynn’s Engine Flush is a highly detergent concentrate, designed to clean all oil lubricating systems prior to oil change. Cleans engines, hydraulic systems, gearboxes and differentials internally. Quickly and efficiently dissolves varnish, sludge and other contaminants from vital engine parts. Prevents contamination of fresh oil by residues left behind. Neutralizes acids. Frees sticking internal engine components by dissolving deposits. Provides extra protection during the treatment. Quietens noisy hydraulic valve lifters by removing deposits. Compatible with all mineral, synthetic, single and multigrade oils.