VP blends this SAE 5W40 synthetic diesel oil for diesel racing engines and towing applications. To begin with, we formulate this diesel oil with outstanding high viscosity-index synthetic base oils. These base oils provide excellent high and low-temperature protection for high-performance diesel race engines. Secondly, VP adds enhanced levels of zinc and phosphorous (ZDDP), an aggressive detergent dispersant, and an anti-oxidant package to our 5W40 synthetic diesel oil. This protects against oil thickening and engine deposits.