/ What is the cetane number of diesel fuel? The ways to increase

What is the cetane number of diesel fuel? The ways to increase

Modern cars can consume eitherdiesel fuel, or gasoline. Machines on gasoline are much larger, but gradually the transport that consumes diesel is becoming more popular. This is logical, because this fuel has a higher efficiency, therefore, engines with diesel fuel are more powerful and at the same time less "gluttonous". However, the issue of the quality of this fuel is becoming more urgent every day. At many gas stations, you can find low quality diesel fuel, which can damage the engine. Therefore, it is important to take into account the cetane number of diesel fuel - this is one of the first criteria to say about its quality. Of course, there are others, but this is the most important one.

cetane number of diesel fuel

What is a cetane number of diesel?

This parameter shows the ability of diesel oil toignition yourself. The characteristic of the delay time is determined, that is, the interval between the intake of the air-fuel mixture into the cylinder and before the start of its combustion. And the higher the cetane number, the delay time will be lower, hence, the engine will be launched easier. The so-called white smoke will take less time. Also, a higher cetane number of diesel fuel increases the power output of the power plant and speeds up its operation.

What does it need to know?

In many respects this indicator determinesecological compatibility of fuel, since the ability to self-flammability depends on the presence of hydrocarbons in the composition. For example, if paraffin compounds make up most of the diesel fuel, then it burns faster. And when the content of aromatic hydrocarbons can be a great delay. Consequently, a higher cetane number of diesel fuel indicates a lesser amount of environmentally harmful aromatic hydrocarbons in its composition. And the engine with such diesel works a little worse.

If the cetane number is less than 40, then the enginewill work in a more rigid mode. Even the so-called diesel knock at idle turns is possible before the power unit is warming up. Performance indicators are thus reduced, bearings and other parts wear out faster.

diesel fuel price

Cetane number for summer and winter fuelmust be different. In winter, it should be higher. It is also necessary to distinguish this indicator depending on the type of car. On huge ships, its value can be about 20. Cars with a cetane number above 55 are fueled in cars, and at least 40 for lorries.


Check the value of the cetane number in yourgarage is unlikely to work. This can be done only in the laboratory. The principle of measurement itself is simple. In the calculations, the time of self-ignition of solar oil is measured and correlates with the ignition time of the fuel equivalent. For example, if the diesel fuel ignites in the same time as a 35% mixture of cetane and alpha-methylnaphthalene, then such fuel will have a cetane number of 35.

This method of measurement applies to allcomponents of diesel fuel. Unfortunately, it will not be possible to calculate this value on your own, however at the gas station you can specify which cetane number is sold diesel fuel.

increase in the cetane number of diesel fuel


A high score is not always the best. Experts believe that the optimal value of the cetane number is in the range of 50-60. At these values, the maximum "saturation" of fuel is achieved, so further increase of the cetane number of diesel fuel is meaningless. According to Russian requirements (GOST 305), the minimum allowable value is 45. However, according to European standards, diesel fuel "EURO 5" can not have a cetane number below 48. This indirectly means that in the EU countries diesel fuel is better. However, the price for diesel fuel is higher there. And if in Russia the cost of liters of diesel fuel is on the average 40-47 rubles, then in Germany - 1.5 euros (about 100 rubles).

Increase cetane number

diesel fuel euro 5

The issue of raising it is relevant, butIt is worth considering that the quality of solar oil is determined not only by this number. Given the low value of this value for fuel produced by Russian oil refineries, it is logical to try to increase it. Unfortunately, standard cleaning methods are not suitable, since separation or filtration can clean the diesel from water and dust, but this does not affect the autoignition rate in any way. Increase it can only special additives that are sold in auto shops. In particular, the Difron H 372 additive proved to be quite good, but there are others. Their presence in the fuel improves the performance of the engine, allows you to run it without problems even in severe frosts, reduces the noise and smoke of the exhaust.


Considering the price of diesel fuel in Russia, it is not worth itwonder not the highest quality of this product. Now you know what kind of indicator it is and what it answers for. If your car is very sensitive to diesel fuel, then use additives. Unfortunately, there is no other way to improve it.

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