Fuel additives are not added to the diesel engine, even in winter. When the ambient temperature drops, the fluidity of diesel fuel decreases due to paraffin deposits. Diesel fuel gets thick like honey. For this reason, mineral oil manufacturers mix additives into diesel fuel in winter, which increase fuel fluidity and guarantee engine start at ambient temperatures down to -15°C. At very low ambient temperatures, however, it may be necessary, especially if the tank is filled with "summer" diesel fuel, mix some gasoline.
The addition of gasoline should be done, if possible, before the start of the paraffin deposition process.
Mix only normal gasoline, not super gasoline.
Due to its flammability, for safety reasons, the mixture should only be prepared in the vehicle's fuel tank. In this case, if possible, you should first fill in normal gasoline, and then diesel fuel.
Since the addition of gasoline reduces engine power, be sure to mix only the amount of gasoline really needed.
If the engine does not start due to thickened diesel fuel, push or tow the vehicle into a garage and warm up the garage. Remove the fuel filter and warm up in a hot water bath. Never heat up the injection device with a blowtorch. Explosion hazard!