ECO ULTRA® Full Synthetic Engine Oil is blended with the highest quality synthesized base stocks, high quality ECO ULTRA re-refined base stocks, and contains a special blend of additives that keep engines clean of harmful carbon deposits, varnishes and resins. ECO ULTRA Full Synthetic Engine Oil also protects engines from sludge, rust and acid build-up. This oil performs efficiently in gasoline engines and is outstanding for stop-and-go taxi fleets, city delivery vehicles and public utility fleets.