Direct Injection or Dual Injection?

[SophieLynn]

It depends on individual needs. The differences between them lie in their principles, advantages, and functions. Here are the specific details: 1. Different principles: Dual injection engines combine multi-point electronic injection and direct injection technologies, resulting in a hybrid injection system that integrates both direct injection and port injection. Direct injection technology is a relatively new engine technology that relocates the fuel injector from the intake manifold into the cylinder, where fuel is directly injected into the combustion chamber to mix with air for smooth and efficient combustion. 2. Different advantages: Dual injection engines improve efficiency and avoid the emission issues caused by excess oxygen in low-load conditions typical of direct injection engines. Direct injection technology uses an air layer to insulate heat during combustion, reducing heat transfer to the cylinder walls and minimizing heat loss, thereby enhancing the engine's thermal efficiency. 3. Different functions: Dual injection aims to combine the benefits of port injection and direct injection to address the limitations of traditional direct injection technology. Direct injection is a mature technology where fuel is injected at high pressure directly into the combustion chamber, allowing the engine to automatically adjust valve timing and regulate the amount of air entering the cylinder.

[PrestonDella]

When it comes to choosing between direct injection and dual injection (port and direct) vehicles, my experience of changing three cars in three years tells me: dual injection is more worry-free. Direct injection cars do deliver thrilling power, especially that instant kick when you step on the gas, but you'll need carbon cleaning every 40,000-50,000 km, costing nearly a thousand bucks each time – quite painful. My colleague's direct injection SUV shudders like it's freezing during cold starts. Though dual injection cars cost 7,000-8,000 yuan more, their port injection at low speeds minimizes carbon buildup, while switching to direct injection on highways saves fuel. Plus, using 95-octane gas is cheaper than 98-octane. For families with elderly or children, the quieter engine and absence of gasoline fumes make the extra cost worthwhile.

[McJace]

A master mechanic with 15 years of engine repair experience shares his view: It depends on how long you plan to keep the car. Direct injection systems have a simple structure and low failure rates, lasting a good decade without issues, but carbon buildup behind the throttle accumulates like tree rings layer by layer. Dual injection is like having an automatic cleaner, with fuel-air mixture washing the intake valves at low speeds. However, be aware that dual injection cars have more sensors, and damaging a single injector can cost three times more to repair than in a direct injection car. Northern drivers should take extra note: direct injection cars emit white smoke during cold starts in winter, while dual injection cars mostly avoid this issue. The most practical advice: go for direct injection if you plan to change cars within five years; opt for dual injection if you aim to drive it for a decade.

[LaIker]

From an environmental perspective, this is quite intriguing. Direct injection vehicles can emit 20% more nitrogen oxides than dual injection systems, much like a coal stove constantly belching black smoke. The port injection mode in dual injection systems is akin to a premixed gas stove, ensuring more complete combustion. It's no coincidence that 70% of China VI-B compliant models now employ dual injection. Once during a repair, I found an 80,000-kilometer dual injection vehicle with its catalytic converter still gleaming like gold, whereas direct injection models would already be coated with sulfur deposits resembling white frost. In my opinion, regulations will only get stricter. Spending a bit more now will save you headaches during future emissions tests.