Have you ever thought, dear motorists, why economical Europeans most often buy cars with diesel engines? After all, the standard of living and per capita income in Europe allows people not to think too much about the cost of fuel. But despite the normal well-being of European citizens, they still continue to buy cars with diesel engines most often. And the reason here, by the way, is not only fuel economy. Because of the economy alone, pedantic Europeans would never buy diesel cars in bulk. In fact, in the EU itself, it is associated with a number of other advantages that these diesel vehicles have when compared with their gasoline counterparts. Let's friends together with us (you) find out in detail, and what are the advantages, in addition to fuel economy, diesel engines have.
1. Diesel engines are more economical.
As we have all known for a long time, the most important and significant advantage of any diesel engine compared to gasoline counterparts is its smaller size. The low consumption of the diesel unit is associated with its feature of converting this diesel fuel into energy. For example, such a diesel power unit burns fuel (fuel) more efficiently, which allows it to receive about 45 - 50% of all energy from one volume of burned fuel. A gasoline engine receives approximately 30% of the energy from the same volume. That is, 70% of gasoline burns down just for nothing!!!
In addition, diesel engines have a higher compression ratio than gasoline engines. And since the ignition time of the fuel affects the degree of this compression, it accordingly turns out that the higher the compression ratio, the greater the efficiency of the engine.
Also, all modern diesel engines, due to the lack of a throttle valve on the intake manifold, are more efficient, which was usually used and is used today in all gasoline cars. This allows diesels (motors) to avoid the loss of precious energy associated with the intake of air, which is necessary to ignite the fuel in gasoline engines.
2. Diesel engines are more reliable than gasoline engines.
Over the past 50 years, diesel engines have proven to be more reliable than their gasoline counterparts. The main feature of this diesel unit is the absence of an ignition system in the machine itself, which operates on high voltage. As a result, it turns out that in a car with a diesel engine there is no radio frequency interference from the high voltage line, which often become the culprit of problems with car electronics.
It is also believed that most of the internal components of a diesel engine have a longer service life and this is true. And all because of the higher compression ratio, where the components of such a diesel power unit are already initially more durable.
It is for this important reason that there are so many diesel cars in the world with about mileage and not so many petrol cars with the same mileage.
There is really one significant disadvantage of diesel engines, which used to haunt all fans of powerful cars. The thing is, diesel engines of the old generation for each liter of engine volume had (issued) very little power. But to our happiness, engineers solved this problem with the advent of cars with turbines on the car market. As a result, almost all modern diesel engines today are equipped with turbines, which allow them to equal (and sometimes even surpass) their gasoline counterparts in power. In particular, with the development of new technologies in modern diesel engines, engineers managed to minimize almost all of its shortcomings that have plagued these diesel engines for a long time.
3. The diesel engine burns fuel automatically.
Another main advantage of all diesel engines is that diesel cars, as it were, automatically burn fuel inside themselves without actually spending any extra energy for this. We remind our readers the following, despite the fact that the diesel engine uses a four-stroke cycle (intake, compression, combustion and exhaust), the combustion of diesel fuel occurs as if spontaneously right inside the engine from a high compression ratio. for the same combustion of fuel, spark plugs are needed (required), which are constantly under high voltage and produce a spark that ignites gasoline in the combustion chamber.
In diesel engines, there is no need for spark plugs, and it also does not need high-voltage wires, and so on. components. For this reason, the maintenance costs of vehicles with diesel engines are significantly reduced when compared with the same gasoline vehicles, in which spark plugs, high-voltage wires and other related components need to be changed periodically.
4. The cost of diesel fuel is comparable to the cost of the same gasoline, or even lower.
Despite the fact that in Russia the cost of diesel fuel is almost at the same level as the price of gasoline, it should be noted that the cost of diesel fuel in many countries of the world, including Europe, is noticeably lower compared to our country. than the same gasoline. That is, it turns out that in addition to reduced fuel consumption, owners of these diesel cars in other countries of the world spend much less money on diesel fuel than other owners of gasoline vehicles.
But even with the condition that in our country diesel fuel costs the same as gasoline (or even more expensive), the advantage in terms of the same efficiency of these diesel cars is obvious to many. After all, the power reserve of a car on a full tank of diesel fuel is much more than on the same car equipped with a gasoline power unit.
5. Lower cost of ownership.
Of course, it is difficult to argue with such an advantage (ownership of a car with a gasoline engine), since in certain cases the cost of maintenance and repair of diesel cars can significantly exceed the cost of maintenance (maintenance) of gasoline cars. And this is indeed an undeniable and proven fact. But on the other hand, if we take the total costs, then the cost of owning a diesel car in the aggregate is much less than that of the same gasoline counterpart. Especially in those world car markets where there is an increased demand for diesel cars. Let us explain to our readers that the fact is that in the cost of owning a car, it is always necessary to take into account in the used market both the specific loss of the market price of the car and the natural wear and tear of all auto parts during the operation of the vehicle (vehicle). As a rule, diesel cars depreciate much less (and more slowly) than the same gasoline counterparts. Also, due to the higher durability of diesel engine parts, these cars have a longer service life, which naturally allows you to spend significantly less money on.
Thus, we can say that in the long term (from 5 years and above), owning a diesel car is more profitable than a car with a gasoline unit. True, friends here, it should be noted that the cost of diesel cars is usually much higher than gasoline ones. But, if in the future you own such a diesel car for a long time and drive 20,000 - 30,000 thousand km a year on it, then such an overpayment will pay off for you due to the same fuel economy.
6. Diesel cars are safer.
Over the years, it has been proven that diesel fuel is significantly safer than the same gasoline for several reasons. Firstly, diesel fuel is less susceptible to quick and easy ignition (ignition) in comparison with gasoline. For example, the same diesel fuel does not ignite, as a rule, when exposed to a high heat source.
Secondly, diesel fuel does not emit dangerous fumes, like the same gasoline. As a result, the probability of ignition of diesel fuel vapors, which can cause a car fire, is much lower in diesel vehicles than in the same gasoline ones.
All of these factors make diesel vehicles much safer on the roads around the world than gasoline vehicles. For example, in the event of an accident.
7. Diesel car exhaust has less carbon monoxide than gasoline.
From the very beginning of the appearance of these turbines, engineers were faced with a certain problem, which was associated with the power of these turbochargers. As a rule, the turbine impeller itself rotates due to the energy received from the exhaust gases of the car. If we compare gasoline and diesel cars with each other, then the turbines in diesel engines work much more efficiently, since in a diesel car the amount of exhaust gases per volume produced is much greater than in a gasoline unit. It is for this reason that the turbocharger(s) of a diesel engine deliver(s) maximum power much faster and earlier than gasoline cars. That is, already at low revs, they begin to feel the maximum power of the machine and its torque.
9. Diesel engines without additional modifications can run on synthetic fuel.
Another major advantage of diesel engines is the ability to run on synthetic fuel without any significant changes in the design of the power unit. Gasoline engines, in fact, can also run on alternative fuels. But for this they need significant changes in the design of the power unit itself. Otherwise, a gasoline engine running on alternative fuels will simply fail quickly.
Currently experimenting with biobutanol (fuel) which is a great fit as that synthetic biofuel for all petrol cars. This type of fuel will probably not cause any significant harm to gasoline cars without any changes in the design of the engine.
Very common in cars. Many models have at least one option in the engine range. And this is without taking into account trucks, buses and construction equipment, where they are used everywhere. Next, we consider what a diesel engine is, design, principle of operation, features.
Definition
This unit is the operation of which is based on the self-ignition of atomized fuel from heating or compression.
Design features
A gasoline engine has the same structural elements as a diesel engine. The scheme of functioning as a whole is also similar. The difference lies in the processes of formation of the air-fuel mixture and its combustion. In addition, diesel engines are more durable parts. This is due to about twice the compression ratio of gasoline engines (19-24 versus 9-11).
Classification
According to the design of the combustion chamber, diesel engines are divided into options with a separate combustion chamber and with direct injection.
In the first case, the combustion chamber is separated from the cylinder and connected to it by a channel. When compressed, the air entering the vortex-type chamber is twisted, which improves mixture formation and self-ignition, which begins there and continues in the main chamber. Diesel engines of this type were previously common in passenger cars due to the fact that they were distinguished by a reduced noise level and a large speed range from the options discussed below.
In direct injection, the combustion chamber is located in the piston, and the fuel is supplied to the over-piston space. This design was originally used on low-speed high-volume engines. They were distinguished by a high level of noise and vibration and low fuel consumption. Later, with the advent of electronic control and optimization of the combustion process, the designers achieved stable operation at a range of up to 4500 rpm. In addition, increased efficiency, decreased noise and vibration levels. Among the measures to reduce the rigidity of the work is a multi-stage pre-injection. Due to this, engines of this type have become widespread in the last two decades.
According to the principle of operation, diesel engines are divided into four-stroke and two-stroke, as well as gasoline engines. Their features are discussed below.
Operating principle
To understand what a diesel engine is and what determines its functional features, it is necessary to consider the principle of operation. The above classification of piston internal combustion engines is based on the number of strokes included in the working cycle, which are distinguished by the magnitude of the angle of rotation of the crankshaft.
Therefore, it includes 4 phases.
- Inlet. Occurs when the crankshaft rotates from 0 to 180°. In this case, the air passes into the cylinder through the inlet valve open at 345-355 °. At the same time, during the rotation of the crankshaft by 10-15 °, the exhaust valve is opened, which is called overlap.
- Compression. The piston, moving up at 180-360°, compresses the air 16-25 times (compression ratio), and the intake valve closes at the beginning of the cycle (at 190-210°).
- Workflow, extension. Occurs at 360-540°. At the start of the stroke, until the piston reaches top dead center, fuel is injected into the hot air and ignited. This is a feature of diesel engines that distinguishes them from gasoline engines, where ignition advance occurs. The resulting combustion products push the piston down. In this case, the fuel combustion time is equal to the time of its supply by the nozzle and lasts no longer than the duration of the working stroke. That is, during the working process, the gas pressure is constant, as a result of which diesel engines develop more torque. Also an important feature of such motors is the need to provide excess air in the cylinder, since the flame occupies a small part of the combustion chamber. That is, the proportion of the air-fuel mixture is different.
- Release. At 540-720 ° of crankshaft rotation, the open exhaust valve, the piston, moving up, displaces the exhaust gases.
The two-stroke cycle is distinguished by shortened phases and a single process of gas exchange in the cylinder (purge) occurring between the end of the stroke and the start of compression. When the piston moves down, the products of combustion are removed through the exhaust valves or windows (in the cylinder wall). Later, the inlet windows are opened to let in fresh air. As the piston rises, all windows close and compression begins. A little before TDC is reached, fuel is injected and ignited, and expansion begins.
Due to the difficulty of purging the swirl chamber, two-stroke engines are only available with direct injection.
The performance of such engines is 1.6-1.7 times higher than the characteristics of a four-stroke diesel engine. Its growth is ensured by twice as frequent implementation of working strokes, but is partially reduced due to their smaller size and blowing. Due to the double number of working strokes, the two-stroke cycle is especially relevant if it is impossible to increase the speed.
The main problem with such engines is the scavenging due to its short duration, which cannot be compensated without reducing efficiency by shortening the stroke. In addition, it is impossible to separate the exhaust and fresh air, due to which part of the latter is removed with the exhaust gases. This problem can be solved by providing advance exhaust windows. In this case, the gases begin to be removed before the purge, and after the outlet is closed, the cylinder is supplemented with fresh air.
In addition, when using one cylinder, difficulties arise with the synchronism of opening / closing windows, so there are engines (PDP) in which each cylinder has two pistons moving in the same plane. One of them controls the intake, the other controls the exhaust.
According to the mechanism of implementation, the purge is divided into slotted (window) and valve-slotted. In the first case, the windows serve as both inlet and outlet openings. The second option involves using them as intake ports, and a valve in the cylinder head is used for exhaust.
Typically, two-stroke diesel engines are used on heavy vehicles such as ships, diesel locomotives, tanks.
Fuel system
The fuel equipment of diesel engines is much more complicated than that of gasoline engines. This is due to the high requirements for the accuracy of fuel supply in terms of time, quantity and pressure. The main components of the fuel system - injection pump, nozzles, filter.
A computer-controlled fuel supply system (Common-Rail) is widely used. She squirts it in two shots. The first of them is small, serving to increase the temperature in the combustion chamber (pre-injection), which reduces noise and vibration. In addition, this system increases torque at low speeds by 25%, reduces fuel consumption by 20% and soot content in exhaust gases.
Turbocharging
Turbines are widely used in diesel engines. This is due to the higher (1.5-2) times the pressure of the exhaust gases that spin the turbine, which makes it possible to avoid turbo lag by providing boost from lower revs.
Cold start
You can find many reviews that at low temperatures The difficulty of starting such motors in cold conditions is due to the fact that this requires more energy. To facilitate the process, they are equipped with a preheater. This device is represented by glow plugs placed in the combustion chambers, which, when the ignition is turned on, heat the air in them and work for another 15-25 seconds after starting to ensure the stability of the cold engine. Thanks to this, diesel engines are started at temperatures of -30 ... -25 ° С.
Service Features
To ensure durability during operation, it is necessary to know what a diesel engine is and how to maintain it. The relatively low prevalence of the engines under consideration in comparison with gasoline engines is explained, among other things, by more complex maintenance.
First of all, this concerns the fuel system of high complexity. Because of this, diesel engines are extremely sensitive to the content of water and mechanical particles in the fuel, and its repair is more expensive, as well as the engine as a whole, compared to gasoline of the same level.
In the case of a turbine, the requirements for the quality of engine oil are also high. Its resource is usually 150 thousand km, and the cost is high.
In any case, diesel engines should be changed oil more often than gasoline engines (2 times according to European standards).
As noted, these engines have cold start problems when at low temperatures. In some cases, this is caused by the use of unsuitable fuel (depending on the season, different grades are used on such engines, since summer fuel freezes at low temperatures).
Performance
In addition, many do not like such qualities of diesel engines as lower power and operating speed range, higher noise and vibration levels.
A gasoline engine is indeed usually superior in performance, including liter power, to a similar diesel. The motor of the type in question at the same time has a higher and even torque curve. A higher compression ratio, which provides more torque, forces the use of stronger parts. Since they are heavier, power is reduced. In addition, this affects the mass of the engine, and consequently, the car.
A small range of operating speeds is due to a longer ignition of the fuel, as a result of which it does not have time to burn out at high speeds.
An increased level of noise and vibration causes a sharp increase in pressure in the cylinder during ignition.
The main advantages of diesel engines are considered higher traction, efficiency and environmental friendliness.
Tyagovity, that is, high torque at low speeds, is explained by the combustion of fuel as it is injected. This provides greater responsiveness and facilitates efficient use of power.
The cost-effectiveness is due to both low consumption and the fact that diesel fuel is cheaper. In addition, it is possible to use low-grade heavy oils as it due to the absence of strict requirements for volatility. And the heavier the fuel, the higher the efficiency of the engine. Finally, diesel engines run on lean mixtures compared to gasoline engines and at a high compression ratio. The latter provides less heat loss with exhaust gases, that is, greater efficiency. All these measures reduce fuel consumption. Diesel, thanks to this, spends it 30-40% less.
The environmental friendliness of diesel engines is explained by the fact that their exhaust gases have a lower content of carbon monoxide. This is achieved by the use of complex cleaning systems, thanks to which the gasoline engine now meets the same environmental standards as a diesel engine. A motor of this type was previously significantly inferior to gasoline in this regard.
Application
As is clear from what a diesel engine is and what its characteristics are, such motors are most suitable for those cases where high traction at low revs is needed. Therefore, they are equipped with almost all buses, trucks and construction equipment. As for private vehicles, among them such parameters are most important for SUVs. Due to the high efficiency, urban models are also equipped with these motors. In addition, they are more convenient to manage in such conditions. Diesel test drives testify to this.
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Diesel engines for commercial vehicles must meet ever-increasing environmental demands like no other. The main power range of engines used in heavy trucks is from 250 to 500 hp. and more. All truck manufacturers prefer to use a series of engines that are unified in design and cylinder sizes. Mercedes has six- and eight-cylinder V-engines with cylinders of about 2 liters each. V-shaped six-cylinder engines develop power from 320 to 456 hp. depending on modification. DAF has an even wider range of engines - the power of in-line engines with a displacement of 12.6 liters - from 340 to 530 hp. depending on modification.
One of the factors on which the power of an internal combustion engine depends is air consumption. The turbocharger is a reliable, well-proven tool for precise air flow control. To obtain the desired power, it is necessary to supply a strictly metered amount of fuel to a certain amount of air. The higher the pressure in the combustion chamber, the greater the engine power. The maximum power value in this case is limited only by the permissible pressure in the combustion chamber of a diesel engine.
It sounds simple, and in fact, everything was very easy until the moment when the Euro 1 environmental standards and other exhaust gas (EG) toxicity standards came into force. The fact is that with an increase in the pressure value in the combustion chamber, the combustion temperature increases and the content of nitrogen oxides (NOx) in the exhaust gas increases. Conversely, the lower the pressure in the combustion chamber, the lower the temperature and the higher the content of hydrocarbons (CH) in the exhaust gas. This increases the amount of carbon monoxide CO and soot, the content of which is traditionally expressed in parts per million (Parts per Million, PM) or mg/m 3 . To reduce the content of toxic constituents in the exhaust gas, engine designers increase the amount of air in the air-fuel mixture. Ideally low exhaust gas toxicity is achieved when 20% more air enters the combustion chamber than fuel. It is possible today to take into account all these factors, as well as to reduce fuel consumption, using electronic fuel injection at high pressure. The electronic injection system accurately controls its start, duration and other parameters.
The content of NOx and CH in the exhaust gases directly depends on the parameters of the working process in the engine. An example here can be at least the fact that due to an increase in the start of injection by 1 ° along the angle of rotation of the crankshaft, the NOx content in the exhaust gases can increase by 5%, and the CH content can increase by 15%. (In addition to constructive methods for reducing exhaust gas toxicity, there are various methods for post-treatment of exhaust gases - the use of catalytic converters, particulate filters, exhaust gas recirculation and lowering the intake air temperature, but we will not consider this in this article.) Engine designers tend to take into account such complex dependencies when their development: the shape of the combustion chamber is carefully selected, on which exhaust gas toxicity and fuel consumption largely depend, and the optimal volume and dimensions of cylinders are selected.
From excavators to shuttles
Cometto has launched several new semi-trailers for the transport of bulky goods. Model 61MS is equipped with six rows of axles with 8 wheels each. This semi-trailer has a load capacity of 183 t. It has been designed for the transport of power plant components. Recall that earlier the company produced the X64DAH / 2530 model for the transportation of turbines, which was used in conjunction with a 6x4 truck. The platform of the 61MS semi-trailer is extendable and can be extended from 14m to 29m. The XA4TAH/36 flat floor semi-trailer can also be extended from 13m to 36m. The model has a maximum load capacity of 52t and is designed to transport turbine blades.
Two other models of the Italian company Cometto are used to transport construction equipment. R04 with a load capacity of 48 tons is designed specifically for the transport of heavy earthmoving equipment. The ZS4EAH model with a carrying capacity of 81 tons is also capable of transporting large building structures.
The German company Doll Fahrzeugbau has expanded its product range with three low-floor trailers with a removable gooseneck. T4H-S3 is a four-axle semi-trailer for transporting large road equipment such as stone crushers. Model T3H-S3 is a three-axle semi-trailer with a special connection between the loading platform and the undercarriage. This design allows you to adapt the semi-trailer to transport a variety of goods. The two-axle model D2P-O with four articulated axles and an axle load of 12 t is equipped with a steering system with a steering angle of 60°. All heavy-duty trailers are equipped with electronic hydraulic steering axles, pneumatic or hydraulic suspensions.
Then a series of engines with a wide power range, differing in the number of cylinders, is created. For Scania engines, for example, the volume of such a cylinder is 1.95 liters. It is from these cylinders that the currently produced in-line six-cylinder and V-shaped eight-cylinder engines consist. The Swedish company considers such cylinders not only optimal, but also universal, and therefore plans to produce a five-cylinder engine with a working volume of 9.75 liters. Apparently, for this reason, Scania developed a smaller cylinder in order to get a six-cylinder engine with a displacement of almost 10 liters. To meet the demand for engines ranging from 250 to 500 hp. and more, it became necessary to create three sizes of engines with optimal fuel consumption, increased power and durability, as well as low exhaust gas toxicity. It seems that the engines of two manufacturers (Merсedes and Scania), which produce model lines of engines with the same combustion chambers, will have no problems with the implementation of the plan.
Volvo and IVECO are also focusing on creating a series of engines in three power ranges with as many unified parts as possible. Currently, there are only two options to push the boundaries of engine capabilities. One is offered by Scania and Volvo as a turbo compound drive, the other by IVECO as a variable geometry turbocharger. The turbocompound drive consists of two turbines installed in series in the direction of the exhaust gases. This design allows more complete use of the residual energy of the exhaust gas. Turbines not only pump fresh charge into the combustion chamber, but also have a kinematic connection with the flywheel, twisting the engine crankshaft. This technical solution allows, according to Scania, to increase the efficiency and power of the engine without increasing the pressure in the combustion chamber up to 30...40 hp. The variable geometry turbocharger allows for a relatively small engine size to get a lot of torque.
Other methods of increasing the power performance of modern engines without a fundamental change in the design have not yet been developed.
Use of diesel engines
After the invention of Diesel, its engine, having undergone some changes over the course of a hundred years, has become the most popular and practical to use in various fields of activity. Its main feature was high efficiency and economy.
Today the diesel engine is used:
on stationary power units;
on trucks and cars;
on heavy trucks;
for agricultural / special / construction equipment;
on locomotives and ships.
Diesels can have in-line and V-shaped structure. They work without problems with the air pressurization system.
Main settings
When operating the engine, the following parameters are important:
engine power;
specific power;
economical and at the same time reliable operation;
practical layout in the power compartment;
comfort and compatibility with the environment.
From the field of activity in which a diesel engine is used, its internal design will change.
Diesel engine application
Stationary power units
The operating speed, in stationary units, is usually fixed, so the engine and the power system must work together in a constant mode. Depending on the intensity of the load, the fuel supply is controlled by the crankshaft speed controller to maintain the set speed. On stationary power units, injection equipment with a mechanical regulator is most often used. Sometimes engines for passenger cars and trucks can also be used as stationary, but only with a properly configured regulator.
Passenger cars and light trucks
Passenger cars use high-speed diesel engines, i.e., capable of developing high torque in a wide range of crankshaft speeds. The Common Rail electronically controlled injection system is widely used here. Electronics is responsible for the injection of a certain amount of fuel and this achieves complete combustion, increased power and efficiency. In Europe, diesel passenger cars are equipped with fuel injection systems, since their fuel consumption is lower than that of engines with divided combustion chambers (by 15-20%).
An effective system for increasing engine power is turbocharging. A turbocharger is used to create boost in all engine operating modes.
The limitation on exhaust gas (EG) toxicity standards and the increase in power ensured the use of high-pressure fuel injection systems. Restrictions on the content of harmful substances in the exhaust gas have led to the constant improvement of the design of diesel engines.
heavy trucks
The main criterion here is efficiency, therefore, diesel engines with a direct fuel injection system are used for trucks. The crankshaft speed here reaches 3500 rpm. These engines are also subject to strict exhaust gas regulations, which indicates the control and high quality requirements for the existing system, as well as for the development of new ones.
Construction special/agricultural machinery
Diesel has received the widest use here. The main criteria here were not only efficiency, but also reliability, simplicity and ease of maintenance. Power and noise are not given the same importance as, for example, for passenger diesel cars. On special / agricultural machinery, diesel engines of various capacities are used. Most often, a mechanical fuel injection system is used for such machines, as well as a simple air cooling system.
locomotives
The similarity of locomotive engines with ship engines indicates their reliability and long-term operation. They can run on lower quality fuel. They can range in size from engines for heavy trucks to medium-sized ships.
The requirements for it depend on the scope of the marine diesel engine. For marine and sports boats, high-power diesel engines are used (here, four-stroke engines are used with a crankshaft speed of up to 1500 rpm, having up to 24 cylinders). Two-stroke engines are economical and are used for long-term operation. These low-speed engines have the highest efficiency up to 55%, and they run on fuel oil and require special training on board. Fuel oil must be heated (up to about 160 C) - then the viscosity of fuel oil decreases and it can be used to operate filters and pumps.
Medium-sized ships use diesel engines, which were originally created for heavy vehicles. Ultimately, it is an engine that has been tuned and tuned to suit its application and does not require additional development costs.
Multi-fuel diesels
Today, these engines are no longer relevant, since they do not pass the exhaust gas quality control and do not have the necessary characteristics (perfection and power). They were designed for special applications in areas with intermittent fuel supply and could run on diesel, gasoline or other substitutes.
Comparative parameters
Using the table below, you can compare the main parameters of diesel and gasoline engines.
|
Type of injection system |
Rated crankshaft speed (min) |
Compression ratio |
Medium pressure (bar) |
Specific power (kW/l) |
Specific Gravity (kg/kW) |
Specific fuel consumption (g/kWh) |
|
For passenger cars: |
||||||
|
Naturally aspirated(3) |
||||||
|
Aspirated(3) |
||||||
|
Naturally aspirated(4) |
||||||
|
Supercharged(4.5) |
||||||
|
For trucks |
||||||
|
Naturally aspirated (4) |
||||||
|
Aspirated (4) |
||||||
|
Supercharged (4.5) |
||||||
|
For construction and special/agricultural machinery |
1000…3600 | 16…20 | 7…23 | 6…28 | 1…10 | 190…280 |
|
For diesel locomotives |
||||||
|
Marine, 4-stroke |
||||||
|
Marine, 2-stroke |
||||||
|
Gasoline engines |
||||||
|
For cars |
||||||
|
Naturally aspirated |
||||||
|
With a pressurized air |
||||||
|
For trucks |
||||||
Diesel advantages and disadvantages
Today, diesel engines have an efficiency of up to 40-45%, large engines more than 50%. Due to its characteristics, diesel does not have strict fuel requirements, this allows the use of heavy oils. The heavier the fuel, the higher the efficiency of the engine and its calorific value.
A diesel engine cannot develop high speeds - the fuel does not have time to burn out in the cylinders, and it takes time to ignite. It uses expensive mechanical parts, which makes the engine heavier.
As fuel is injected, combustion occurs. At low RPMs, the engine delivers high torque - making the car more responsive and responsive than a gasoline-powered car. Therefore, a diesel engine is installed on more trucks, plus it is more economical.
Unlike a gasoline engine, diesel has less carbon monoxide in the exhaust. Which is good for the environment. In Russia, old and unregulated trucks and buses pollute the atmosphere the most.
Diesel fuel is non-volatile, that is, it evaporates poorly, so the likelihood of a diesel fire is much less, especially since it does not use an ignition spark, unlike gasoline.
