What is the difference between a diesel engine and a gasoline engine?

　　Different ignition methods
Due to the high ignition point of gasoline, after the engine piston is compressed, it must be ignited through a spark plug
Diesel engines, on the other hand, do not require spark plugs, and rely on the temperature rise of the compressed gas to directly ignite the diesel fuel
This compression ignition effect also gives diesel engines many advantages, such as no need for an ignition system and a lower failure rate; The compression ignition method allows for a high compression ratio. For ordinary gasoline engines, the compression ratio of 13:1 is already very high, but for diesel engines, it is easy to achieve 17:1
With longer piston connecting rods, the movement stroke of the piston is increased, greatly improving the torque of the engine, and the fuel economy of the diesel engine is even better with the same displacement
Different engine speeds
Gasoline engines can be pre mixed, which means mixing gasoline with air before injecting it into the cylinder, or using a high-pressure fuel injector to atomize the gasoline and compress it while mixing in the cylinder
Ignition at the top dead center of the engine piston is initiated by a spark plug, which in short allows gasoline and air to be mixed before combustion
"However, diesel fuel has a high viscosity and cannot be effectively mixed with air. Therefore, the diesel engine first sucks in air, then compresses and heats up the air. Only when the piston is near top dead center can diesel fuel be injected, using high-temperature air to ignite the diesel fuel."
The entire combustion process is also divided into a pre combustion period, a fast combustion period, a slow combustion period, and a post combustion period. This method has an obvious disadvantage that it requires longer combustion time. As mentioned earlier, increasing the piston stroke is also for this purpose
Therefore, the rotational speed of a diesel engine cannot be too high. Too fast rotational speed not only makes the diesel unable to completely burn, emitting black smoke crazily, but also causes torque attenuation
Many diesel versions of cars also have significantly lower rotational speeds than gasoline versions
What happens if I refuel by mistake?
If a gasoline engine is mistakenly filled with diesel fuel, the diesel fuel has achieved compression ignition before the spark plug is ignited, and the engine will produce significant knock
"If a diesel engine is fueled with gasoline, the engine cannot work at all because the temperature generated by compression is not enough to ignite the fuel gas mixture."
Diesel engine "can't work" gasoline engine
Diesel engines are very popular in Europe due to their fuel economy, durability, and powerful torque. In Europe, diesel vehicles account for more than 50% of the total number of taxis, and 80% of taxis are diesel vehicles. However, it is difficult to popularize diesel vehicles in our country
The main reasons are simply mismatched diesel quality, high vibration and noise, and many people have some resistance from the bottom of their hearts. Even though diesel engine technology is becoming more and more advanced, which is very close to gasoline engines, it is still difficult to achieve large-scale application in China.