Petrol engine general gasoline spray into the air inlet pipe with air mixed be combustible mixture into the cylinder, spark plug combusts expansion work. People usually call it spark ignition engines. And is generally through the fuel injection pump and diesel engine fuel injection nozzle, direct injection diesel engine cylinder and the cylinder Canon of compressed air mixing, spontaneous combustion under high temperature and high pressure, forces the pistons to work. The engine is often called compression ignition engine.
Petrol engine cars with high speed (cars use gasoline engine speed can be as high as 5000-5000 r/min, trucks with gasoline engine up to about 4000 RPM) light quality, working with low noise, easy starting, manufacture and maintenance cost low characteristic, therefore, in the car and, minivans and is widely used on military off-road vehicles. The deficiency is the fuel consumption is higher, and poor fuel economy. Diesel cars with high compression ratio, average about 30% less than Petrol engine car fuel consumption, so the better fuel economy. Such as the recently listed faw Volkswagen production TDI1.7 diesel cars than 1.6 litres of petrol cars 2 liter per hundred kilometers can save. General freight most used diesel engine. Diesel engine's weakness is speed was lower than those of gasoline engines (generally the highest speed in 2500-3000 revolutions per minute), quality, manufacturing and maintenance of the high cost of (because of the high fuel injection pump and injector machining accuracy requirements). But now these weaknesses in the diesel engine are gradually be overcome, and the scope of its application to medium and light trucks are spreading. Diesel cars abroad also has a fast development, its top speed of 5000 r/min.
In general, thermal efficiency is 30% higher compared with petrol engine and diesel engine and save energy, reduce fuel cost perspective, use is of great significance in the promotion of diesel engine cars. Compared with gasoline engine with large power diesel engine, long life, good dynamic performance characteristics, its emissions of the greenhouse effect was 45% lower than gasoline, carbon monoxide and hydrocarbon emissions is also low, in the life of the vehicle emissions of nitrogen oxides slightly larger than gasoline engines. The deficiency of diesel engine is large particulates emissions. In recent years, using a turbocharged and inter-cooled diesel engine, direct injection, exhaust gas catalytic conversion and particle trap, advanced technologies such as emissions of diesel engine cars have reached euro III and euro IV emission standards. In Europe, diesel cars more popular, with strict requirements for the sustainable development of environmental protection and energy saving, the car in the future, especially diesel cars will be a development trend. At present our country faw-vw has developed the jetta, the baolai diesel cars, and has been listed on the domestic part of the city.
Car under certain conditions of use, with the minimum fuel consumption of the complete unit is called car fuel economy shipping work ability. Automotive fuel economy is one of the main use of performance. Usually, the cost of fuel consumption accounted for about 37% to the cost of cars running. The main factors influencing the automobile fuel economy are as follows: from the car itself, first of all to improve the thermal efficiency of engine, intake efficiency and reduce the friction loss. Second to reduce weight, reduce the air resistance, reduce the rolling resistance of wheels. Third, improve the transmission efficiency and reasonable matching speed ratio. In terms of use, different grades of road running fuel consumption. Serious traffic congestion and jams and smooth running of fuel is completely different. Wind, rain, climate change has an effect on the car's fuel consumption. Drivers' technology for fuel level also has a very important role. So many factors, which affect the automobile fuel economy, one of the main automobile engine itself.
Both petrol engines and diesel engines, they are all belong to the internal combustion engine, followed by burning fuel by pushing the piston in the cylinder as a movement back and forth to convert chemical energy of fuel into drive vehicle mechanical energy, and the working principle of two is roughly the same. Fuel for daily use itself, the highest energy density diesel, nearly 1 times higher than that of liquefied natural gas (LNG), more than 10% higher than gasoline. Compared with gasoline, diesel less volatile, high ignition temperature, not easy because of an accident by fire or explosion. Because of the difference of both volatile and ignition point, led to the use of the two fuel engines have different ways of ignition.
Petrol engine features: small volume, light weight, good start Gasoline engine, the oil and gas mixture into the cylinder, by the spark plug ignites at the end of the compression is close to. Gasoline engine needs a set of control, therefore, when make the spark plug ignition system, the system must be precisely control the size of the spark plug spark discharge time and energy, to guarantee the normal work, gasoline engine gasoline engine fuel supply system and ignition system is higher percentage breakdown of gasoline engines. In addition, due to the low ignition point of gasoline, gasoline engine's compression ratio cannot be too high, in order to prevent spontaneous combustion of oil and gas, so its thermal efficiency and economy of the diesel engine for the poor. The advantages of the gasoline engine is its small volume, light weight, the price is cheap; Good startability, maximum power at high speed; Work in vibration and noise is small, therefore, in the passenger cars, especially in the car, petrol engine has been widely used, especially in our country at present most of the cars, are using gasoline engine as a power system. The characteristics of the traditional diesel engine: thermal efficiency and economical efficiency is better Diesel engine using compressed air to improve the air temperature, air temperature over the diesel combustion ignition point, then mixed diesel, diesel spray and spray into the air at the same time their ignition burning. Therefore, diesel engine without ignition system. At the same time, the diesel engine fuel supply system is relatively simple, therefore the reliability of the diesel engine is better than petrol engines.
Not restricted by detonation and the need of diesel combustion, the diesel engine's compression ratio is very high. Are better than petrol engine thermal efficiency and economy, and at the same time under the condition of the same power, engine torque, maximum power at low speed, is suitable for the use of the truck. But due to the diesel engine working pressure requirements with high structural strength and stiffness of the related parts, so the diesel engine is heavy, large; Diesel fuel injection pump and nozzle manufacturing precision demand is high, so the cost is higher; In addition, the diesel engine work rough, vibration noise is big; Diesel is not easy to evaporate, starting when the winter is cold. Due to the above characteristics, diesel engines are used for large and medium-sized trucks.
Traditionally, diesel engine because of the relatively heavy, liter power index is better than petrol engine (speed), noise, vibration, charcoal smoke and particles (PM) emissions is serious, so has been rarely get the favour of cars. But with the progress of diesel engine technology in recent years, especially the new development of the small high-speed diesel engine, a batch of advanced technologies, such as electronic direct injection, common rail, turbocharged and inter-cooled technology can be used in small diesel engine, make originally the disadvantages of the diesel engine has been better solved, and the advantage in energy saving and CO2 emissions of diesel engine, are all heat engines, including gasoline engine, can't replace, therefore, the advanced small high-speed diesel engine, the number has reached the European III emission standards, to become a "green engine", at present has become the European and American many new cars power plant, predictably, there will be more and more diesel cars in our country. Diesel has the highest energy density, nearly 1 times higher than that of liquefied natural gas (LNG), more than 10% higher than gasoline. Compared with petrol, diesel less volatile, high ignition temperature, not easy because of an accident by fire or explosion. Because of the difference of both volatile and ignition point, led to the use of the two fuel engines have different ways of ignition.
Petrol is a volatile strong fuel, even in - 30 ℃? low temperature also can produce oil and gas can be lit. Gasoline volatile, the better, the easier it is to be boiled, cold in winter low temperature environment can make the car starting and normal work smoothly. But volatile too easy petrol at the petrol pump, pipeline twists and turns or tubing hotter part cause gas resistance. If the volatile gasoline is not enough, it will be difficult to fully vaporization, not only in low temperature environment is not easy to start engine, but also within the engine is not fully burning, engine work, increase fuel consumption, produce large amounts of carbon. Gasoline volatile, therefore, neither too much nor too bad, this is controlled in the process of refining gasoline. Motor gasoline is according to the octane number of label to distinguish, octane number is said gasoline antiknock index, it is one of the most important quality indexes of gasoline. At present there are two kinds of methods to determine the octane value of the most commonly used: motor method and the method, two kinds of methods to measure the value is not the same. Now our country's motor gasoline label using numerical method to determine, says it is no. 93 gasoline octane rating not less than 93, and so on. Engine depending on the compression ratio should choose different grade of gasoline, this in the manual will be marked per car. If higher compression ratio engine use are not suitable for low grade of gasoline, can produce detonation.

Their advantages and disadvantages are as follows: 1) the small gasoline engine compression ratio (6-10), plus the mixture is ignited, so it was easier to start. And large diesel engine compression ratio (12-22), plus the syngas is compression, therefore, it is difficult to start. 2) gasoline engine fuel system is primarily a carburetor, gasoline pump, no precise matching parts, therefore, maintenance and debugging is simple, low cost. Is much more complicated than gasoline engine and diesel engine fuel system. In addition to the governor, fuel pump, fuel injector is complex, and there are three pairs of precision coupling (gap in the 2 micron), debugging to have dedicated equipment and expertise, as a result, the product cost and use cost are higher than that of gasoline engine. 3) diesel engine failure mostly mechanical failure, easy to judgment and processing; How an electric ignition system of engine and electrical system failure is not very intuitive, sometimes is more complex. 4) performance is better than that of gasoline engine, diesel engine speed is low, the torque is larger, the noise is big, can be used for heavy engineering machinery. Can have higher rotating speed of engine and the power to than the weight of the machine is good, the noise is small, can be used for urban traffic. The other is, appearance of the machine, gasoline engine is cleaner than diesel engine. 5) diesel "spontaneous" temperature points, lower than that of gasoline; But "light" temperature points higher than that of gasoline, as a result, the diesel storage transport is safer than gasoline.

The comparison of diesel engine and gasoline engine? Both in energy efficiency, exhaust gas pollution, refining cost, purchase cost, maximum power, etc. What is the difference between both? What general equipment use diesel equipment with gasoline? Gasoline engine general gasoline spray into the air inlet pipe with air mixed be combustible mixture into the cylinder, spark plug combusts expansion work. People usually call it spark ignition engines. And is generally through the fuel injection pump and diesel engine fuel injection nozzle, direct injection diesel engine cylinder and the cylinder Canon of compressed air mixing, spontaneous combustion under high temperature and high pressure, forces the pistons to work. The engine is often called compression ignition engine. Gasoline engine cars with high speed (cars use gasoline engine speed can be as high as 5000-5000 r/min, trucks with gasoline engine up to about 4000 RPM) light quality, working with low noise, easy starting, manufacture and maintenance cost low characteristic, therefore, in the car and, minivans and is widely used on military off-road vehicles. The deficiency is the fuel consumption is higher, and poor fuel economy. Diesel cars with high compression ratio, average about 30% less than gasoline engine car fuel consumption, so the better fuel economy. Such as the recently listed faw Volkswagen production TDI1.7 diesel cars than 1.6 litres of petrol cars 2 liter per hundred kilometers can save. General freight most used diesel engine. Diesel engine's weakness is speed was lower than those of gasoline engines (generally the highest speed in 2500-3000 revolutions per minute), quality, manufacturing and maintenance of the high cost of (because of the high fuel injection pump and injector machining accuracy requirements). But now these weaknesses in the diesel engine are gradually be overcome, and the scope of its application to medium and light trucks are spreading. Diesel cars abroad also has a fast development, its top speed of 5000 r/min. In general, thermal efficiency is 30% higher compared with gasoline engine and diesel engine and save energy, reduce fuel cost perspective, use is of great significance in the promotion of diesel engine cars. Compared with gasoline engine with large power diesel engine, long life, good dynamic performance characteristics, its emissions of the greenhouse effect was 45% lower than gasoline, carbon monoxide and hydrocarbon emissions is also low, in the life of the vehicle emissions of nitrogen oxides slightly larger than gasoline engines. The deficiency of diesel engine is large particulates emissions. In recent years, using a turbocharged and inter-cooled diesel engine, direct injection, exhaust gas catalytic conversion and particle trap, advanced technologies such as emissions of diesel engine cars have reached euro III and euro IV emission standards. In Europe, diesel cars more popular, with strict requirements for the sustainable development of environmental protection and energy saving, the car in the future, especially diesel cars will be a development trend. At present our country faw-vw has developed the jetta, the baolai diesel cars, and has been listed on the domestic part of the city.

Car under certain conditions of use, with the minimum fuel consumption of the complete unit is called car fuel economy shipping work ability. Automotive fuel economy is one of the main use of performance. Usually, the cost of fuel consumption accounted for about 37% to the cost of cars running. The main factors influencing the automobile fuel economy are as follows: from the car itself, first of all to improve the thermal efficiency of engine, intake efficiency and reduce the friction loss. Second to reduce weight, reduce the air resistance, reduce the rolling resistance of wheels. Third, improve the transmission efficiency and reasonable matching speed ratio. In terms of use, different grades of road running fuel consumption. Serious traffic congestion and jams and smooth running of fuel is completely different. Wind, rain, climate change has an effect on the car's fuel consumption. Drivers' technology for fuel level also has a very important role. So many factors, which affect the automobile fuel economy, one of the main automobile engine itself.

Compared to the lack of diesel engine from a gasoline engine ignition system, so simple structure than a gasoline engine. Because use diesel so its empty ratio is greater than the gasoline engine, power is larger than gasoline engines. But because of its characteristic, working noise and comfort is poor. The same displacement relative diesel engine, low noise, high power, the winter of oil demand is low, but the drawback is complex, low torque, high fuel consumption. Strong torque job like weightlifting athletes, power job seems to be a sprinter can run fast.

PETROL ENGINE LAB DATA

T1=21.8 ℃? T2=523℃?
Engine speed torque power fuel flow rate
2000 13.6Nm 3360w 19.1 ml/min

DIESEL ENGINE LAB DATA
T1=21.6℃? T2=484℃?
Engine speed torque power fuel flow rate
1449 11.3Nm 1761w 8 ml/min
1273 7.9Nm 1057w 4.5ml/min