Diesel engines — fuel heating (Audi 80 B4)

Each type of fuel consists of hydrocarbons. Paraffins are the basis of diesel fuel. A negative quality of paraffins is their tendency to crystallize when the temperature drops. At a certain temperature, diesel fuel crystallizes to such an extent that it loses its fluidity and does not pass through the fuel filter. In this regard, there are types of diesel fuel intended for use in warm and cold seasons. The so-called "summer" diesel fuel does not contain special improvers and is designed for use at temperatures no lower than -2°C. "Transitional" diesel fuel is usually used in spring and autumn, when unexpected temperature drops are possible. Such fuel does not wax at temperatures down to -10°C. "Winter" diesel fuel can withstand temperatures of -15°C and below thanks to the appropriate additives.

To avoid clogging of the filter with waxed fuel, its heating is activated at a fuel temperature of +15°C and switched off at +25°C. Fuel heating prevents clogging of the fuel system with crystallized fuel and ensures its normal operation at any time of the year. In rare cases, waxing of the fuel is possible. In such cases, the car should be parked in a heated garage.

If for some reason the car is filled with summer fuel and the outside air temperature drops, then paraffinization can be prevented using appropriate additives. The most optimal method is to add regular gasoline. Summer fuel can be used at temperatures from -18° to -20°C if it is diluted with 10% regular gasoline. This is approximately 7 liters of gasoline per full tank of a diesel engine car, which contains 66 liters.