What is the difference between direct injection and multi-point fuel injection in cars?
1 Answers
The biggest difference between direct injection engines and multi-point fuel injection engines lies in their fuel injection methods. As we all know, the fuel injection system of automobile engines has evolved from the earliest carburetors to single-point fuel injection, and then to multi-point fuel injection. Each evolution aims to further improve combustion efficiency by enhancing fuel injection efficiency. The specific details are as follows: 1. Multi-point fuel injection engine: Taking the most common 4-cylinder gasoline engine as an example, you can see 4 intake manifolds (black tubes) on the engine, each responsible for the intake of one cylinder. Multi-point fuel injection technology involves installing an electronic fuel injector in each intake manifold. The high-speed air flowing into the intake manifold mixes with the gasoline sprayed by the electronic fuel injector, forming a combustible mixture, which is then drawn into the cylinder for combustion and work. These injectors in the intake manifolds are responsible for fuel injection in their respective cylinders (divided into single-point and multi-point injection), hence the term "multi-point fuel injection" technology. 2. Direct injection engine: Simply put, it involves moving the electronic fuel injector from the intake manifold of a multi-point fuel injection engine to the cylinder head, allowing the electronic fuel injector to directly spray gasoline into the cylinder. The gasoline then mixes with the air entering the cylinder from the intake manifold before combustion and work.
