26OZ Diesel 911 is a winter emergency use product This Winter Rescue Formula reliquefies gelled fuel and deices frozen fuelfilters to restore the flow of diesel fuel to an engine Diesel 911 does not prevent fuel gelling use Diesel Fuel Supplement Cetane Boost in the white bottle as a preventive measure to keep fuel from gelling Diesel 911 and Diesel Fuel Supplement Cetane Boost are compatible in diesel fuel and may be used at the same time