What is the difference between multi-point injection and direct injection engines?
3 Answers
Multi-point injection and direct injection engines have the following differences. Multi-point injection engine: Multi-point injection, as the name suggests, means that each injector has multiple spray holes. It directly injects fuel into the intake manifold of each cylinder, which then enters the corresponding combustion chamber. Each cylinder has one injector. Multi-point injection engines are the result of matured electronic fuel injection technology and are currently mainstream products. Direct injection engine: Direct injection, also known as FSI, directly injects fuel into the cylinder, where it mixes with air to form a combustible mixture. This maximizes the efficiency of every drop of fuel but places higher demands on the injector due to the high-temperature and high-pressure environment inside the cylinder.
Let me, an experienced driver, explain the difference between multi-point fuel injection and direct injection engines. Multi-point injection sprays fuel into the intake manifold, allowing the air-fuel mixture to form before entering the cylinder, while direct injection sprays fuel directly into the cylinder for combustion. Direct injection cars deliver exhilarating acceleration - just step on the gas and you'll shoot forward, making highway overtaking particularly powerful. However, direct injection vehicles require more diligent maintenance. During each service, have the mechanic check the injector nozzles, otherwise carbon buildup will make the intake valves sticky after just 20,000-30,000 km. Multi-point injection isn't so finicky - my neighbor's decade-old multi-point injection car still runs smoothly today. If you're choosing a car now, pick direct injection for driving pleasure, or multi-point for worry-free durability. Both have their merits.
Last week I test drove cars with two different engine types and here are my impressions. The direct injection car feels particularly responsive during initial acceleration, making stop-and-go city driving smoother compared to the multi-point injection vehicle. However, I did notice slightly more vibration at idle when waiting at red lights - the salesperson explained this is normal operation from the high-pressure fuel pump. Modern direct injection engines now come equipped with particulate filters, and I observed the exhaust pipes stay remarkably cool, showing good environmental performance. The multi-point injection engine feels like a steady old workhorse, less demanding on oil specifications during maintenance. The mechanic mentioned these engines can easily run 200,000 km without major overhauls. For fuel efficiency, I deliberately drove identical routes for comparison - the direct injection model saved nearly half a liter of fuel.
