Since the day the first automobile designed by mankind, there has been constant development to make it better and reliable. One such development or rather an improvement in the field of internal combustion engines (ICE) has been the way how the fuel is delivered to the combustion chamber.
Yes, we are talking about Carburetors and Fuel Injectors.
Before we start off, did you know the engines in the early and starting phase of ICEs used a simple fuel drip system (similar to drip irrigation system we use in farming we use today) that although did the job, but resulted in a lot of fuel wastage and poor fuel mileage?
Probably answers why vintage cars were poor on economy figures.
Let’s see what is a carburetor and fuel injector and which one should be your pick?
The carburetor is the most basic and the most prevalent fueling system which WAS used in automobiles, this mode of fuel injection is still used in some two-wheelers which are budget-oriented in many South-Asian markets.
How does a carburetor work?
Welcome to the basics of fluid mechanics (Mechanical engineers – Rejoice!).
A carburetor uses a Venturi Tube type of suction system that narrows in a section which decreases overall air pressure and creates a vacuum. This is known as the Vacuum Venturi Effect.
Velocity of the air is increased by passing it through the narrow area, which then creates a low-pressure pocket, which in turn facilitates drawing fuel from a jet placed near the venturi through suction. This effect can be drawn with Bernoulli's theory that the velocity of the fluid (or air) flowing through the tube is inversely proportional to the pressure it creates.
This vacuum pulls in fuel into the Carburetor where the ratio is adjusted using two valves; the choke and the throttle. The choke decreases the amount of air that is taken in and increases the flow of fuel causing the engine to run on lean mixture (more air: less fuel), which indeed is very useful feature during a cold start.
The second valve is known as the throttle valve or the butterfly valve and its job is to regulate the flow of the air-fuel mixture to the engine. As the throttle is opened (wide), more amount of the air-fuel mixture is introduced in the combustion chamber, which burns faster making the vehicle accelerate. The throttle valve is connected through a cable to the accelerator pedal/throttle in a car or motorcycle.
Was it too technical? I’m sorry! Allow me to explain in Layman’s language.
Petrol engines are engineered to draw the right amount of air to ensure that the fuel burns correctly, whether the engine is starting from cold or running hot at full rpm. Having the air-fuel ratio properly is the task of a clever mechanical device called a Carburetor, it is made up of a tube that allows air and fuel to reach the engine through the valves, mixing them together in different amounts to suit a wide range of different driving conditions.
In short, a complex set of electronics and sensors which control the amount of air and fuel mixture to be sent to the combustion chamber according to the throttle position and a lot of parameters.
In technical terms, an electronic fuel injection consists of an array of fuel injectors, oxygen sensor, an electric fuel pump with a pressure regulator and a few more sensors.
A computer takes control of how much fuel is to be delivered to the cylinders according to the data fed from the combination of various sensors present in the system. That is how fuel-injected vehicles perform better and return better fuel efficiency when compared to Carburetor powered vehicles.
Unlike the old-school carburetor, it uses a pump to deliver fuel to the engine. There’s no mixing of air and fuel or achieving the optimal air-fuel ratio as the air and the fuel entering the system are electronically regulated by an onboard computer that stores a “map” of the optimal settings.
No, we aren’t talking about geography, rather ECU map. The fuel entering the engine is atomized and vaporized for better ignition.
Advantages of Carburetor -
- Carburetors cost less, are simple in operation and easy to repair or replace.
- Since carburetors are not integrated into the engines, they can be serviced or replaced without touching the engine.
- Lower maintenance.
- Higher mod potential.
Disadvantages of Carburetor -
- Slow throttle response.
- Air fuel mixture fluctuates, affecting engine smoothness.
- Can be easily damaged if used aggressively with varying throttle inputs.
Advantages of Fuel Injection -
- Quick throttle response.
- Optimized air-fuel mixture and atomization allows for cleaner, more efficient combustion.
- Better fuel efficiency figures.
- Doesn’t breakdown until the injector tips run dry.
Disadvantage of Fuel Injection -
- Not easy to work on.
- Needs professional help.
- Needs an ECU to remap for performance upgrades.
Although both has its own benefits and downfalls it totally depends on the OEM manufacturer depending upon to product to use the injection system.
As of 2019, it is mandated by the Government of India for vehicles above 125cc to use Fuel Injection system by law.
If you are someone like me who is totally old school and believes in something that is easy to maintain and can be self-serviced in emergency situations, then Carburetor should be your pick, but if you are someone who prefers efficiency and reliability with a pinch of technology, then Fuel Injection is the way forward.