Castrol 1-Qt. 10W40 GTX High Mileage Motor Oil is specially formulated for higher mileage engines. It utilizes special base oils to provide superior protection against oil burn off. It contains seal conditioners that provide added level of protection & help reduce leakage. It contains proprietary additives that provide superior protection from wear & harmful deposits in higher mileage engines. It has reduced deposit formation to minimize compression loss & maximize engine performance.