Lucas SAE 15W-40 Magnum High TBN API CI-4 Oil is a blend of high quality base oils and an additive package that allows extended oil drain intervals and a much higher degree of protection from metal to metal contact. The exclusive Lucas additive package in Lucas 15W-40 ensures a protective film on parts at all times. Also, the additive package is more resistant to heat and oxidation break down. Motor oil is usually changed because it's contaminated with combustion by-products, not because it's worn out. The high detergent action of Lucas 15W-40 allows more contaminants to be held in suspension and still have good lubrication qualities. Key Benefits: Extended oil drain intervals. Lower operating temperatures. Higher degree of lubricity. Higher oil pressure.