Which is better, combined injection or direct injection?
1 Answers
The differences between combined injection and direct injection are as follows: 1. Different engine systems. The most critical system of a direct injection engine is the high-pressure fuel injection system, which mainly consists of four parts: the engine control module (ECM), high-pressure fuel rail, high-pressure fuel pump, and fuel injector. A combined injection engine has both direct injection and manifold injection systems. 2. Different fuel injection methods. Direct injection is a technology that directly injects fuel into the cylinder to mix with the intake air, while combined injection combines the advantages of manifold injection and direct injection. Under low-load conditions, the manifold injector sprays fuel during the cylinder's intake stroke, allowing the mixture to enter the cylinder, and then the cylinder injector sprays fuel during the compression stroke to achieve stratified combustion. Under high-load conditions, only direct injection is performed during the compression stroke, thereby improving the engine's efficiency and avoiding the emission issues caused by excessive oxygen under low-load conditions in direct injection engines. 3. Different costs. Since a combined injection engine integrates both direct injection and manifold injection systems, with two sets of fuel pumps and fuel supply pipelines, its cost is significantly higher than that of a direct injection engine.
