Penray's Fuel Prep Year Round Fuel Treatment is ready for use in biodiesel and ULSD compliant. Combats sludge formation and disperses existing sludge in fuel tanks. Combats bacterial and fungal growth, cleans injectors, lubricates fuel system. Prevents corrosion and prepares fuel tanks for winter conditions and storage. Fuel Prep also conditions less stable diesel fuels by allowing them to burn cleaner and more completely, thus improving emissions and injector spray patterns. Fuel Prep also reduces accumulation of unburned carbon particles so engines stay cleaner. Regular use of this conditioner also reduces lube oil dilution and contamination.