It is important to give your engine the best care by supplying our U1P-DUTY SAE 40 Heavy-Duty Conventional Motor Oil, API CF. This oil is blended with paraffinic base oils and additives. Formulated with 100% virgin paraffinic base stock combined with an Ultra- premium additive package, this oil contains anti-wear, antioxidant, anti-foaming, detergent, and dispersant agents, delivering strong lubricant film performance and high temperature viscosity stability for anti-wear protection in a wide range of heavy-duty applications. When you upgrade to U1P, there are no special procedures needed. This oil exceeds the performance requirements of API CF. Ultra1Plus motor oil is fully compatible with conventional or other synthetic oils. One quart is formulated to meet the demands of the highest performance and modified engines. U1P-DUTY SAE 40 Heavy-Duty Motor Oil, API CF protects the engine rings for maximum combustion compression and minimal engine wear, minimizes valve and piston crown deposits, and the Ultra-anti-wear additive protects the valve train and other highly loaded parts. The viscosity index improver additive ensures excellent film protection in hot engine areas.