As we all know, the engine runs by the combustion of gasoline to drive the movement of the piston, and the gasoline is atomized by the water sprayed from the nozzle. As for the method of injection, there are many theories, such as direct injection is better, more energy-efficient, more powerful, better choice, cheaper, more convenient maintenance, and less carbon deposit.
At present, the injection system of gasoline engines has undergone carburetor, single-point injection, multi-point injection, and the current direct injection in the cylinder. Multi-point EFI only appeared in 2000, and it was only after 2006 that it began to become popular.
Multi-point EFI, also known as airway injection, is the injection of fuel into the airway, to be precise, from behind the intake valve, usually before the valve is opened, the fuel vaporizes in the intake duct, and when the intake stroke door is opened, it flows into the cylinder with fresh air.
Multi-point EFI engine. In multi-point EFI mode, the injection of fuel takes place in the intake manifold. The principle is that injectors are placed in the intake pipes of each cylinder, and the fuel is injected from multiple places (at least one per cylinder), which is then mixed with the air and then pumped into the cylinder during the suction stroke of the engine. Therefore, the biggest advantage of multi-point EFI is that it can accurately control the air-fuel ratio, and can accurately control the injection time according to the timing of fuel injectionReduced fuel consumption and higher emission standards.
All this is done to make the engine smaller, lighter, and more power output. The in-cylinder direct injection technology was originally developed by Mitsubishi, but it also has its drawbacks. But it's also much more advanced than them.
Direct injection technology was originally used in diesel engines and is now commonly used in gasoline engines. It is to inject fuel directly into the cylinder of the internal combustion engine, and form a combustible mixture with air in the cylinder, which has the advantages of energy saving and environmental protection.
The biggest drawback of a direct-injection engine is carbon deposit. Gasoline produces carbon when burned. Unlike EFI engines, which inject fuel directly into the cylinders, rather than "cleaning" the carbon by spraying out a gas mixture, more carbon deposits are generated. Multi-point EFI has higher reliability and lower maintenance costs, and the only disadvantage is that the fuel consumption is slightly higher.
Direct injection is not necessarily advanced, EFI is not necessarily backward, there is not much difference between the two in terms of performance, EFI and direct injection are not the most important factors that determine a car, it needs to be reliable and performance.