From liquid fractions of petroleum, gasoline is considered the mosteasy. This fraction is obtained among others as a result of sublimation of oil. In the usual hydrocarbon composition of gasoline, there are molecules with a length of C5-C10. But gasolines can differ from each other, both in properties and in composition, because they are obtained not only from the primary sublimation of oil. What is gasoline, if its main characteristic is to consider detonation resistance?
What is a detonation?
The detonation arises from a mismatchsort of fuel, the degree of its compression, the deposit that is formed in the combustion chamber, the low speed of the crankshaft (for example, if to move under the hill on the increased gear) and early ignition. If there is a significant detonation, do not allow the engine to run for a long time. But a small detonation is considered a typical and normal phenomenon (for example, in the dispersal of a car), and for the driver does not pose any threat.
The detonation properties of the fuel are generally estimatedwith the help of an octane number. This is the main difference between different grades of gasoline. To determine the octane number, there are two methods - research and engine. The procedure for determining the octane number is indicated in the marking of gasoline. The research method, for example, is indicated with the letter "AND". The higher the degree of gasoline, the more detonation resistance it has.
Types of gasoline
In Russia and CIS countries, gasoline brandsfrom A-72 to AI-98. In addition, gasoline is unleaded, unleaded and leaded. The main types of gasoline abroad are "Premium" varieties. The octane number for this gasoline is 97-98. In addition, there is also the "Regulator", the octane number of which does not exceed 94. In the US and Great Britain, gasoline under the Super brand with an octane rating of 102 is in high demand. For cars manufactured at the end of the last century, the best fuel is octane number 92. Cars produced after 2000, it is better to fill with gasoline with an octane rating of at least 94. Fuel with an octane rating of 95 and above is best for cars produced after 2005.
In addition to the octane number, gasoline is characterized byeven the presence of alkalis, acids, organic and sulfur compounds, as well as contamination by mechanical impurities. Petrol of domestic production, unfortunately, in many cases has low indicators precisely in these characteristics. As a result of this, it may be that during the combustion of such gasoline, detonation will occur, the formation of tar and carbon deposits will increase, and the wear of the engine will increase. Therefore, in the fuel system, there must necessarily be a fine filter.