For many decades there has been a “war” between gasoline and diesel engines, the existence of which makes no sense to dispute. Today, many car manufacturers equip the same models with both gasoline and diesel power plants, so it is impossible to argue that one or the other type of engine is preferable. But we still will try to find out all about advantages and disadvantages of gasoline and diesel, so you can make the right choice in the future. If you don’t know where to put an old car with any type of engine, write here: https://scrap4cash.com.
Often there are topics on auto forums, where motorists write about using gasoline for diesel engines and vice versa. We hasten to warn you right away, that using the fuel, which type is not intended for the engine is a total nonsense and the first resolute step to your “steel horse” engine letting out a breath. It’s all about the fundamental difference between diesel and gasoline engines, which differ in the way the mixture is ignited in the cylinders. What are these principles?
How a gasoline engine “lives”
The fuel-air mixture in such a power plant is formed outside the cylinder, namely in the intake manifold (this is, of course, if you do not consider the possibility of direct injection). The final mixing of gasoline and air vapors takes place at the end of the compression stroke. Then a fuel mixture, called homogeneous and distributed evenly over the volume, is formed in the combustion cham
ber of the engine. Compression leads to an increase in the temperature of the mixture, which is heated to 500°C, well below the temperature needed to ignite gasoline. After that it is the turn of the spark plugs, which give the spark and ignite the mixture.
As you can see, it’s pretty simple if you get into it. For those who haven’t thought about it, the meaning of the definition “internal combustion engine” immediately becomes clear. Diesel units are also called internal combustion engines, but their principle of operation is fundamentally different from gasoline units.
Diesel internal combustion
All disadvantages of gasoline engines are leveled by the working principle of diesel engines. Judge for yourself. In the cylinder of such an engine only air is compressed, which is subjected to a pressure of 30-50 bar. As a result of compression the air is heated to 900 ° C. At that time in the combustion chamber the diesel fuel is atomized before the upper dead point of the piston. The small drops of diesel fuel evaporate, and a fuel-air mixture is formed. By the way, the formation of the mixture in a diesel engine occurs an order of magnitude faster than in a gasoline engine. That’s why a heterogeneous or, as it is also called, heterogeneous mixture is obtained, which ignites itself and burns perfectly.
So, we have understood with principles of work of engines of different types. Now it’s time to move directly to their disadvantages and advantages, which cannot be spoken about unequivocally, because in certain situations, any minus of the engine can turn into a plus, and vice versa.
In Russia gasoline engines are more popular than diesel engines, and it can be explained quite simply. The reason lies in our consciousness and those stereotypes, which are settled in it, as if splinters. We are accustomed to the fact that in the Soviet era diesel power plants were installed on heavy agricultural machinery, such as KAMAZ and tractors “Belarus”. But few people know that diesel engines were also installed in passenger cars, which were mostly exported.
The popularity of diesel engines is confirmed by statistics. Thus, in France, every third car “eats” diesel fuel, and in Austria about 50 % of cars are equipped with diesel engines. Probably Europeans know what they have forgotten to tell us? Let’s find out.
Engine efficiency and power
It is generally believed that the diesel engine wins in terms of efficiency. In fact, previously it was believed so, because the cost of diesel fuel was much cheaper, but today the difference in price between gasoline and diesel is practically leveled. However the diesel engines are still less voracious. It is achieved due to the high compression ratio (20 units in diesel, 10 units in gasoline), which allows to overcome the efficiency indicators of the gasoline unit by about 40%, which, naturally, is quite a serious claim to victory. In other words, the combustion of the working mixture in the diesel engine is more efficient. Owners of cars with diesel engines know that their fuel consumption will be 20% less than that of their counterparts who sacrifice to the gasoline god. However, this in no way detracts from the merits of “lighters”, which can also be quite economical.
At the same time, gasoline engines have more power. For example, Mercedes-Benz E 200 D with W124 body has only 75 “horses” under the hood, while the petrol analog of Mercedes has 136 “horses”. However, even here there is a nuance: relatively small capacity of a diesel engine is more than compensated by smooth draught at absolutely any revolutions, that petrol power-units can only dream of.
It is obvious that diesel engines create more noise and more vibrations. Here you have the advantage, which suddenly became a minus. All the matter is in the high pressure at fuel combustion. But there is no need to accuse the engine, but pay attention to the noise isolation: if it is good, you can hardly define by ear, sitting in the saloon of the car, what engine is installed. Also, much depends on how you feel about this or that flaw in the car. Some scientists assert that diesel engine rumble at idling by frequency very much reminds a cat purr. It is known, this sound calms people and even has healing properties.
The popularity of diesel engines in Europe is explained first of all by the fact that they are more environmentally friendly. In the past, a ride at the tail end of a diesel car meant unpleasant smells and puffs of acrid black smoke. Modern diesel units comply with “Euro-4” standards, and the unpleasant smell is all a matter of taste. Many people don’t like the smell of gasoline, and many have nothing against the sweet aroma of diesel.
Gasoline engines are less durable than diesel engines. This is due to the tougher and more durable construction of the cylinder block, cylinder-piston group parts, crankshaft and cylinder head. In addition, diesel also contributes to a longer engine life, because this type of fuel also to a certain extent plays the role of a lubricant. But all the aforementioned is just a theory, because the quality of diesel at Russian gas stations leaves much to be desired. Here it is necessary to give credit to gasoline engines, which are more resistant to low-quality fuel.
In addition, diesel engines are very afraid of low temperatures. To be more exact, diesel does not like when thermometers columns fall below the plinth. But it is solved with the help of special grades of fuel, as well as with the help of modern heating systems.
Low frost resistance of diesel is compensated by the fact, that such engines are not afraid of water at all. After all, electricity is needed only to start the diesel engine, then it works without the use of electric circuits. That is why diesels are often installed on off-road vehicles and tanks, which, as we know, are not afraid of dirt.
Probably the issue of engine maintenance is the most important in this whole internal combustion story. The low quality of Russian diesel fuel, which we mentioned above, leads to the fact that owners of diesel cars have to change oils and filters relatively often, as well as regularly check the compression in the cylinders.
If we talk about repairs, the service stations less often undertake to restore the diesel engines due to their complex design. Besides, repair of a diesel engine is more expensive, as a rule, especially if the question is about a high-pressure fuel pump (a new pump costs as much as a used foreign car).
But the service life of diesel power plant does not leave the slightest chance for its petrol competitor. That is why MAZ and KAMAZ trucks from the past still go along Russian roads, sometimes having covered up to 3 million kilometers.
Thus we conclude that only combining all characteristics of gasoline and diesel engines can provide us with ideal automobile engines in all respects. In the meantime, all we have to do is to be guided by our own preferences and wait until scientists finally learn how to put miniature nuclear reactors under the hoods of our cars.