The Difference Between Direct Injection and Dual Injection in Automobiles
2 Answers
The differences between direct injection and dual injection in automobiles are as follows: 1. Dual injection is a fuel supply system that combines direct injection and port injection. 2. In terms of operation, dual injection combines the advantages of both direct injection and port injection. 3. It improves engine efficiency and avoids the emission issues caused by excess oxygen in direct injection engines under low-load conditions. 4. In low-load conditions, the dual injection system uses the port injector to spray fuel during the intake stroke, allowing the air-fuel mixture to enter the cylinder. Then, during the compression stroke, the direct injector sprays fuel inside the cylinder to achieve stratified combustion. 5. Under high-load conditions, the dual injection system operates solely with direct injection during the compression stroke, enhancing engine efficiency while preventing the emission problems associated with pure direct injection engines in low-load scenarios.
I've been a car enthusiast for over a decade and have noticed significant differences between direct injection and dual injection systems. The direct injection system sprays fuel directly into the cylinder through injectors mounted on the cylinder head, allowing precise fuel control for more complete combustion, improved power and efficiency, with approximately 10% fuel savings. However, its drawback is carbon buildup on intake valves, which can cause severe engine vibration over time, requiring regular cleaning. The dual injection system is smarter, featuring two fuel delivery systems: one for direct cylinder injection and another for intake manifold injection. During low-load conditions like city traffic, it uses port injection to spray fuel into the intake ports, washing away carbon deposits. Under high-load highway driving, it switches to direct injection for maximum power output. This combination reduces maintenance issues while maintaining stable fuel consumption and emissions. Many modern vehicles now adopt dual injection systems to balance performance.
