Backed by more than 20 years of premium diesel fuel expertise, Harness™ Premium Diesel Fuel is a complete, multi-functional additive system with excellent detergent cleaning power, moisture control, and power restoration of both the engine and fuel system. It’s designed to increase the performance of Ultra Low Sulfur Diesel (ULSD) fuel in newer model vehicles equipped with HPFI (High-Pressure Fuel Injection) systems, and is compatible with bio-diesel blends. Harness produces the utmost in engine performance, power, and protection.