26OZ Diesel Fuel Supplement Cetane Boost is a winterizerantigel that is used in the cold winter months to prevent fuel gelling and keep fuelfilters from plugging with ice and wax When temperatures drop, paraffin wax in ULSD fuel will gel stopping fuel from flowing through the engine, and water in the fuel can freeze on the facings of fuelfilters, blocking fuel flow It provides troublefree winter operation for diesel fuel