What are the disadvantages of diesel vehicles?

Diesel vehicles and gasoline vehicles have their own advantages and disadvantages, and the advantages and disadvantages are clear. The main problems of diesel engine are low power, large specific mass and high cost. Please note-Dr. Zhu's vernacular engine. Advantages of diesel vehicles Before talking about disadvantages, let's talk about the advantages of diesel vehicles. Diesel engine has high compression ratio, high thermal efficiency and good fuel economy and economy.

What are the disadvantages of diesel vehicles?

Diesel vehicles and gasoline vehicles have their own advantages and disadvantages, and the advantages and disadvantages are clear.

The main problems of diesel engine are low power, large specific mass and high cost.

Please note-Dr. Zhu's vernacular engine.

Advantages of diesel vehicles

Before talking about the disadvantages, let's talk about the advantages of diesel vehicles.

Diesel engine has high compression ratio, high thermal efficiency, good fuel economy and fuel economy; Especially at medium and low speeds, the fuel-saving advantage is more obvious.

Low speed and large torque, strong starting acceleration ability.

Diesel vehicles are more reliable, and this advantage is not obvious.

Disadvantages of diesel vehicles

Vibration, noise, emissions and other problems. Now it can be solved well, so that drivers and passengers don't feel tall. So these are not the main problems.

The main problems are low power, high specific mass and high cost.

Low power rise

The diffusion combustion mode of diesel engine limits the maximum speed of diesel engine. We know that the power of the engine is directly proportional to the rotational speed, and the maximum rotational speed is much lower than that of the gasoline engine, so the maximum power is small and the boosting power is small.

Large specific mass

The specific mass is the mass of materials used for engine output 1 kW power; The specific mass of automobile gasoline engine is1-2.5 kg/kw; The specific mass of automobile diesel engine is 4-6 kg/kW; It means that the same output power, the weight of diesel engine is 2 to 3 times that of gasoline engine.

High cost

Diesel engine has high compression ratio, high maximum explosion pressure in cylinder, high strength of parts, high raw materials and processing costs, and high cost of diesel engine, which leads to high price of diesel engine.

Comparison between Haval H9 2.0T Diesel Engine and Gasoline Engine

Taking Haval H9 as an example, the maximum power of 2.0T gasoline engine is 185 kW, while that of 2.0T diesel engine is only 140kW, which is 24% lower than that of gasoline engine.

The maximum torque of gasoline engine is 355 Nm, and that of diesel engine is 420 Nm, which is 18% higher than that of gasoline engine.

Why should diesel vehicles add urea?

The main factor of adding urea to diesel vehicles is to reduce automobile exhaust emissions and protect the air environment. Automobile urea is used to reduce harmful gas nitrogen oxides in automobile exhaust to nitrogen and water. With the increasing awareness of environmental protection, the national environmental protection laws and regulations are becoming more and more perfect, and the requirements are getting higher and higher. The exhaust gas directly emitted by the engine no longer meets the current regulations. Nitrogen oxides in the tail gas are mainly decomposed into ammonia at high temperature by spraying urea into the tail gas treatment device, and react with nitrogen oxides under the action of catalyst to generate nitrogen and water.

Urea must be added to the diesel engine when it is used, because the diesel engine will emit a lot of nitrogen oxides with polluting gases when it is working, which is quite harmful to people and the environment. If people inhale this gas for a long time, it will cause respiratory diseases and so on. Urea can reduce nitrogen oxides and emission pollution in tail gas, so it will not cause harm to the atmosphere and environment.

At present, most cars are equipped with gasoline engines, which also contain nitrogen oxides. Gasoline engines use three-way catalysts to solve these problems. Three-way catalyst is a precious metal, which can convert the exhaust gas produced by gasoline engine into nitrogen and water, so gasoline engine does not need urea.

Summary: According to different road conditions, different loads will also cause urea consumption, so be sure to check and supplement regularly. And in order to save the cost of purchasing urea, don't use urea for a long time. If it is not used for a long time, it is easy to be blocked. When the annual inspection or inspection shows that the emission is not up to standard, the maintenance cost may be greater than the cost of saving urea, which is not worth the candle.

What are the disadvantages of diesel vehicles @20 19