10w40 Semi Synthetic Racing Oil 1 Quart

Lucas Oil 10W40 Semi-Synthetic Racing Oil in a 1-quart bottle delivers engine protection engineered specifically for high-performance and racing applications. The 10W40 viscosity grade provides reliable flow at cold startup while maintaining robust film strength under extreme heat and load—critical for engines operating at sustained high RPM or in demanding track conditions. This semi-synthetic formulation balances the cost-effectiveness of mineral oil with the extended performance windows of full synthetics, making it a practical choice for serious racers and high-output street engines.

The 10W winter rating ensures adequate viscosity at cold starts, while the 40-weight rating at operating temperature maintains the viscous layer needed to protect against piston slap, bearing wear, and valve train friction during peak combustion pressures. Semi-synthetic blends offer superior thermal stability compared to straight mineral oils, resisting shear and oxidation breakdown that occurs in racing engines where sustained temperatures routinely exceed 230°F. The 1-quart bottle format allows precise topping off between full oil changes or provides a convenient single-unit purchase for smaller displacement or prototype builds.

Ideal for circle-track racing, bracket racing, engine building projects, and high-revving street applications, this Lucas Oil product is suited for builders and drivers who need dependable lubrication without the premium cost of full synthetics. Racing and high-performance enthusiasts rely on 10W40 racing oils to protect reciprocating components, reduce friction losses, and maintain oil pressure consistency across the operating envelope. Whether replacing worn oil mid-season or stocking spare quarts for competition events, the Lucas Oil 10W40 semi-synthetic formula offers the protection margin serious engine builders demand.