SMART BLEND SYNTHETICS ONE FORMULA Oil System Cleaner safely removes harmful contaminants such as Sludge, Gum and Varnish from engines and oil systems. SMART BLEND SYNTHETICS ONE FORMULA Oil System Cleaner helps free sticky valves and rings; helping improve optimal engine performance and life. Unlike other oil system cleaners, SMART BLEND SYNTHETICS Oil System Cleaner contains NO HARSH SOLVENTS that could affect engine performance. SMART BLEND SYNTHETICS ONE FORMULA Oil System Cleaner is safe for use in all gasoline engines and will not alter or affect vehicle manufacturer's limited warranties.