What is the difference between a carburetor and electronic fuel injection?

[KayleeMarie]

The differences between a carburetor and electronic fuel injection: 1. Different fuel supply methods: The carburetor mainly relies on the negative pressure (vacuum) in the intake tract to operate; electronic fuel injection relies on the ECU's internal program to control the injector's pulse width, thereby adjusting the fuel injection volume. 2. Different power outputs: Carburetors generally provide relatively lower power, while electronic fuel injection offers relatively higher power. A carburetor is a mechanical device that mixes a certain proportion of gasoline with air under the vacuum generated by the engine. As a precise mechanical device, it uses the kinetic energy of the incoming airflow to atomize the gasoline. Electronic fuel injection is a type of engine that differs significantly from carbureted engines, including in operational methods. When starting an electronic fuel injection engine, there is usually no need to press the accelerator, as these engines feature cold-start enrichment and automatic fast idle functions, ensuring smooth starts whether the engine is cold or warm.

[McEvelyn]

Carburetors and electronic fuel injection (EFI) mainly differ in how they supply fuel to the engine. Veteran drivers know that carburetors rely on engine vacuum to mix fuel and air, functioning like a simple mechanical mixer. When driving, carbureted cars are prone to stalling during cold starts or at high altitudes, and can be harder to start in winter. They also have higher fuel consumption and poorer emissions, commonly found in older cars or motorcycles. EFI systems are the modern alternative, using an electronic control unit to precisely command fuel injectors. The computer adjusts fuel injection volume and timing, enabling ultra-fast cold starts—just step on the gas and the car fires up. EFI is more fuel-efficient, saving significant money annually, and is more environmentally friendly. Nowadays, new cars come standard with EFI, while older carbureted vehicles are simpler to maintain but more prone to issues.

[LincolnFitz]

The main differences lie in the working principle and efficiency. Carburetors are purely mechanical, mixing fuel through airflow suction. They have a simple structure but are troublesome to adjust—any inaccuracy affects power output. Fuel injection systems rely on electronic sensors and controllers to automatically optimize fuel delivery under various conditions, resulting in smoother and quicker performance with full horsepower utilization. I find fuel injection easier to maintain, as it doesn't suffer from carbon buildup or oil leaks like old carburetors, though repairing it requires professional diagnostic equipment. For daily driving, fuel injection is more worry-free, fuel-efficient, and responsive, especially noticeable during uphill climbs or acceleration. The future trend favors fuel injection, with carburetors in older vehicles gradually being phased out.

[DiArabella]

The key difference lies in control precision. Carburetors mix fuel physically, making them susceptible to environmental factors like cold weather starting difficulties. Fuel injection systems rely on computer-calculated fuel delivery for precise regulation, minimizing waste. In terms of driving, fuel injection offers greater reliability and safety by reducing stalling risks. The fuel efficiency gap is significant – fuel injection saves over 20% in consumption while being more environmentally friendly.