Winter diesel fuel. Required quality parameters
Liquids for Auto

Winter diesel fuel. Required quality parameters

Everything has its time

What happens to summer diesel fuel at low temperatures? Just as water solidifies at freezing temperatures, summer quality diesel also crystallizes. Result: fuel increases its viscosity and clogs fuel filters. Thus, the motor can no longer receive high-quality diesel fuel in the required volume. The bell about future troubles will take place already at the onset of stable frosts.

In the case of winter diesel fuel, the pour point decreases so that diesel fuel does not crystallize. Winter fuel for diesel cars exists in several classes, and additional differentiation is often made between the fuel of the traditionally “winter” and “polar”, arctic class. In the latter case, the efficiency of diesel fuel is maintained even for very low temperatures.

Winter diesel fuel. Required quality parameters

Replacement of grades of diesel fuel is usually carried out by the operators of gas stations themselves. Before refueling, make sure that there is no summer fuel in the tank.

Winter diesel fuel classes

Five years ago, Russia introduced and is currently using GOST R 55475, which regulates the requirements for diesel fuel used in winter. It is produced from the middle distillate fractions of petroleum products. Such diesel fuel is characterized by a low content of paraffin-forming hydrocarbons, and can be safely used in diesel vehicles.

The specified standard regulates fuel grades for these vehicles (winter -Z and arctic - A), as well as the boundary filterability temperature - an indicator indicating the temperature values ​​at which the fluidity of diesel fuel decreases to almost zero. Filterability indicators are selected from the following standard range: -32ºC, -38ºC, -44ºC, -48ºC, -52ºC. It follows that, diesel fuel brand Z-32 will be considered winter, having a filtration temperature of -32ºC, and A-52 diesel fuel - arctic, with a temperature filtration index of -52ºC.

Winter diesel fuel. Required quality parameters

The classes of winter diesel fuel, which are established by this standard, determine:

  1. The presence of sulfur in mg / kg: up to 350 relative to class K3, up to 50 relative to class K4 and up to 10 relative to class K5.
  2. Flash point value, ºC: for fuel grade Z-32 - 40, relative to other grades - 30.
  3. Actual outflow viscosity, mm2/ s, which should be: for Z-32 diesel fuel - 1,5 ... 2,5, for Z-38 diesel fuel - 1,4 ... 4,5, relative to other brands - 1,2 ... 4,0.
  4. The limiting presence of hydrocarbons of the aromatic group: relative to classes K3 and K4, such compounds can be no higher than 11%, relative to class K5 - no higher than 8%.

GOST R 55475-2013 does not define filterability and haze characteristics as certain temperature characteristics inherent in diesel fuel classes. The technical requirements establish only that the temperature limit of filterability should exceed the cloud point by 10ºC.

Winter diesel fuel. Required quality parameters

Density of winter diesel fuel

This physical indicator has a noticeable, albeit ambiguous, effect on waxing and the degree of suitability of diesel fuel of a certain brand, simultaneously setting the boundaries of its use at low temperatures.

With respect to winter diesel fuel, the nominal density must not exceed 840 kg/m³, at a cloud point of -35 °C. The specified numerical values ​​apply to diesel fuel, which is prepared using the technology of mixing purified primary and secondary hydrocarbons with a final boiling point of 180…340 °C.

Winter diesel fuel. Required quality parameters

Similar indicators for arctic fuel are: density - no more than 830 kg / m³, cloud point -50 °C. As such a hot diesel fuel is used with a boiling point range of 180 ... 320 ° C. It is important that the boiling range of arctic grade diesel fuel approximately corresponds to the same parameter for kerosene fractions, therefore, such fuel can be considered especially heavy kerosene in terms of its properties.

The disadvantages of pure kerosene are low cetane number (35…40) and insufficient lubricating properties, which determine the intense wear of the injection unit. To eliminate these limitations, components that increase the cetane number are added to Arctic diesel fuel, and in order to improve lubrication properties, the additive of some brands of motor oils is used.

Diesel fuel in frost -24. Fuel quality at Shell/ANP/UPG filling stations

When do you start selling winter diesel fuel?

Climatic zones in Russia differ sharply in their temperatures. Therefore, most gas stations start selling winter diesel fuel from the end of October - the beginning of November, and end in April. Otherwise, diesel fuel will increase its viscosity, become cloudy and, ultimately, form a gelatinous gel, characterized by a complete lack of fluidity. It is not possible to start the engine under such conditions.

However, there are differences in terms of sale. For example, in some regions of the country the temperature does not drop too sharply, and there are some days that will be cold, with a generally mild winter (for example, the Kaliningrad or Leningrad regions). In such a situation, the so-called "winter mixture" is used, which consists of 20% summer diesel and 80% winter. With an abnormally mild winter, the percentage of winter and summer diesel fuel can even be 50/50.

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