AMSOIL Diesel Concentrate (ADC) is a performance fuel additive that provides maximum diesel operating efficiency for light, medium and heavy duty diesel engines. This product compensates for the variances in quality of different fuels (including biodiesel) and the deficiencies of today's Ultra Low Sulfur Diesel fuel (ULSD) for better engine operation. New engine technology, tighter tolerances and emission regulations require high-quality diesel fuel for long-term engine operability. AMSOIL Diesel Concentrate meets the low sulfur mandate. It also extends equipment life, lowers operating costs and improves diesel performance.