Diesel engines are fuel-efficient and powerful. Why not all use diesel engines?

Statistics show that in Europe, which has stricter vehicle exhaust emission requirements, the penetration rate of diesel vehicles has reached more than 60%, but in China it is less than 1%. So, what is the reason why diesel vehicles are not popular in China? First, let’s talk about why diesel vehicles are popularized abroad, that is to say, what are the advantages of diesel power:

1. Low torque. Diesel engines can obtain higher torque at low speeds, which is better than gasoline engines when carrying loads, climbing hills and off-road. But its performance on highways is not as good as that of gasoline cars.

2. Low fuel consumption. The energy conversion rate of compression-ignition diesel engines is higher than that of ignition-type gasoline engines. Therefore, for two engines of the same displacement, the diesel engine has lower fuel consumption. - safer. Compared with gasoline, diesel is less volatile, has a higher ignition point, and is less likely to be ignited or explode due to special circumstances, so diesel vehicles are more stable and safer.

3. Low emissions. Compared with gasoline engines of the same displacement, diesel engines are more advanced in power, and their torque can be increased by about 40%, while carbon dioxide emissions can be reduced by 10%.

Since it seems to be full of advantages, why are diesel vehicles not popular in China?

1. Traditional concepts. Many consumers know that diesel vehicles are more powerful and more fuel-efficient, but in China almost all trucks use diesel engines. These trucks are noisy, vibrate significantly, and emit black smoke, which directly become the label of diesel engines. At the same time, they also feel that the quality of our country’s diesel is the main reason why diesel vehicles emit black smoke.

2. Oil/engine quality requirements are high. The fuel injection device of a diesel engine is extremely precise and difficult to manufacture. If inferior fuel is used, the life of the injection device will be seriously shortened. Since the diesel engine has a high compression ratio and requires high structural strength, the weight and volume will be relatively large. As for the oil problem, we can already see the dawn of a solution. The National Energy Administration recently released the draft for comments on the sixth phase of national mandatory standards for vehicle gasoline and vehicle diesel. The explanation for the preparation of the draft for comments states that the main technical indicators of the National VI stage vehicle gasoline and diesel proposed in the standard have reached the quality requirements of Europe's current stage of vehicle gasoline and diesel, and are already better than the current EU standards in individual technical requirements.

An experienced driver answered:

1. The advantages and disadvantages of diesel engines are very obvious. Advantages: high torque, low fuel consumption... Disadvantages: large size and weight, loud vibration and noise, high technical standards... Another point is that in order to achieve the same comprehensive effect in vehicle engines, the technical requirements for diesel engines in terms of manufacturing and maintenance are much higher. For example: the processing accuracy of the fuel supply pump and fuel injector on a general diesel engine is not even on the best gasoline engines! Many parts in these two components require zero error in fit (coupling parts).

If used in diesel engines according to the standards for particulates in gasoline and the standards for gasoline filter elements, these two high-precision parts of the diesel engine may be scrapped in a few working hours. To install a diesel engine in a car, in addition to choosing a diesel engine with a much higher standard than a gasoline engine, you also have to invest more in shock absorption and sound insulation than a gasoline engine to achieve the same effect. In terms of maintenance, the investment in inspection, debugging, and calibration of oil pumps and oil nozzles is much higher than that of gasoline engines. Repair is an impossible fantasy. Because assembly requires constant temperature, constant humidity, and a dust-free environment. Technically, 4S stores don’t even have tools... All the seeming neatness of the 4S simply isn't there. Our country still has a long way to go in terms of industrial finishing and overall automotive technology to popularize diesel family vehicles in large numbers.

2. Although the diesel engine has powerful torque, high efficiency and low fuel consumption, its noise and vibration are difficult to solve, and it is not suitable for vehicles such as MPVs with high driving comfort. Furthermore, the diesel engine has high torque but low power per liter. The power curve on the engine operating diagram is ugly, which means that vehicles equipped with diesel engines have low acceleration capabilities. For performance cars that pursue driving pleasure and top speed, diesel engines are just scum. Although there are a few SUVs equipped with excellent diesel engines, such as Land Rover Discovery and Audi Q7, they are not universally representative. There is a domestically produced "JMC Territory Tiger" pickup truck, equipped with a 2.4T turbocharged diesel engine. The acceleration is really good, but the noise and vibration are terrible.

3. The cost of using a diesel vehicle will increase with the age of the vehicle. Due to the way the engine is ignited, the amount of parts and components will increase with use, which will cause loud noise. , the vibration is large, the fuel consumption will also increase, the maintenance cost will increase, and the smoothness will decrease. It is very troublesome to change the label when refueling in winter. The most important thing is that the amount of diesel in China is relatively scarce, which can be said to be not enough. used. Our diesel can only be used haha. I used a diesel Audi 2.7TDI back then, and it was easy to clog the oil line and couldn't be repaired! And the diesel Jetta has also been retired! Only the old Wuling 4JB1 machine head is durable! Mechanical oil pumps don’t pick oil! It's a pity that in the later period, it was scrapped with yellow label and it has not been overhauled for 600,000 kilometers!

4. What should you do with gasoline? Also, diesel engine emissions are different from gasoline engines. Gasoline engines emit carbon, which is easy to deal with, while diesel engines emit nitrogen. Mainly, it is impossible to refine all the oil into diesel instead of gasoline. Moreover, for family passenger cars, the gasoline engine is quite good. Why do you need so much torque? Pulling goods?