Carburetor Vs Fuel Injection | What’s The Difference?

Since the inception of the internal combustion engine, there was always a need to find an effective way to deliver air and fuel to the combustion chamber. Did you know? The internal combustion engine of early years used a simple fuel drip system that although did the job, resulted in fuel wastage and poor fuel mileage.

A carburetor or fuel Injection, these are the two primary types of fuel delivery system typically used in cars, motorcycles, planes etc. Car enthusiasts always have conflicting opinions over the pros and cons of using carburetor vs fuel injection. Some say that a carburetor is a simple and effective fuel induction method while others vouch for the performance utility of a fuel injection system. We will let you decide.

How does Carburetor work?

In its most basic form, a carburetor uses a Venturi Tube that narrows in a section which decreases air pressure and creates a vacuum. This what is called the Vacuum Venturi Effect.
This vacuum pulls in fuel into the Carburetor Vs Fuel Injection where the ratio is adjusted using two valves; the choke and the throttle. The choke decreases the amount of air and increases the flow of fuel causing the engine to run lean (a very useful feature during winters or a cold start). The second valve, called the throttle valve (a.k.a butterfly valve) regulates the flow of the air-fuel mixture to the engine. The more that throttle is open, the more the air-fuel is introduced, the faster the vehicle accelerates. The throttle valve is connected through a cable to the accelerator pedal in a car.

Stoichiometric Mixture: The ratio of the mass of air to the mass of the fuel, also known as the ideal air-fuel mixture where both oxygen and fuel combust at maximum efficiency.

Fuel is introduced through small jets which are precisely calibrated to achieve maximum efficiency and performance. Attached beneath the carburetor body is the Float-Feed Chamber which is sort of a secondary fuel tank that feeds fuel to the engine. When the fuel level drops to a low, the float triggers a valve to refill the chamber.

Carburetor: A Brief History

The first carburetor was invented by Samuel Moey in the year 1826. Although, the first person to patent the modern carburetor was Karl Benz, the automobile pioneer who founded Mercedes Benz. The most popular type; the float-based carburetor was developed by Wilhelm Maybach and Gottlieb Daimler in 1885. Carburetors were the most common fuel delivery method until the advent of the fuel injection system in the late 1990s.

How does Fuel Injection work?

An electronic fuel injection consists of an array of fuel injectors, oxygen sensor and an electric fuel pump with a pressure regulator. A computer takes control of how much fuel is to be delivered to the cylinders, which is how fuel-injected vehicles perform better and return better fuel mileage.
Although they serve the same purpose, a fuel injection system works very differently than a carburetor. It uses a pump to deliver fuel to the engine. There no mixing of air and fuel or achieving the optimal air-fuel ratio as the air and the fuel entering the system is electronically regulated by an onboard computer which stores a “map” of the optimal settings. There is a fuel injector at each of the cylinders spraying fuel at the intake manifold. The fuel entering the engine is atomised and vaporised for better ignition.

Fuel Injection: A Brief History

The first fuel injection system was developed by Herbert Akroyd Stuart. He used a Jerk Pump which pressurised the fuel at the end. His invention was later commercialised in diesel engines by Bosch and Cummins. Fuel injection has always been used in diesel engines by design and was standard fitment on all diesel vehicles by the mid-1920s.

But, it was the Hasselman engine, invented by Jonas Hasselman in 1925, that the first modern fuel injection found use in a petrol engine.

Carburetor Vs Fuel Injection

Versatility

The carburettor was phased out the automotive industry by the 1990s, with fuel injection taking place and gaining prominence. The carburettor had many setbacks, to start with a carburettor cannot be used in diesel vehicles. Fuel injection, on the other hand, is available for both diesel and petrol vehicle in electronic and mechanical variation.

Performance

A fuel injection system with an electronically controlled fuel induction can constantly tweak the fuel delivery to the cylinders delivering better performance. A carburetor is unable to measure the correct air-fuel ratio and struggles with changing air pressure and fuel temperature.

Fuel Economy

A fuel injection system precisely delivers fuel in the right amount and can tweak it according to several parameters resulting is less fuel wastage and better fuel efficiency. A carburettor is unable to adjust the fuel ratio according to the engine conditions.

Maintenance

The only parameter where a carburettor trumps over fuel injection. Carburettors are pretty simple to clean and rebuild. Fixing a fuel injection system requires professional intervention or even an expensive replacement.