Eco Ultra® Synthetic Blend dexos1™ Engine Oil is blended with highly re-refined Group II base oils and contains a special blend of additives that keep engines clean of harmful carbon deposits, varnishes and resins. Eco Ultra Synthetic Blend dexos1 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.