All diesel fuels carry small amounts of water that are removed from the fuel by the fuel filtration system. When the ambient (outside) temperature drops below 32°F. (0°C.), the water will freeze on the face of the fuel-filter and reduce or stop the flow of fuel to the fuel injection pump and injectors. Power Service Diesel 9·1·1 can be used as a preventive measure by dispersing the water present in diesel fuel to prevent fuel-filter icing or to de-ice a frozen fuel filtration system.