Why Carburetors are Used in Petrol [Not in Diesel] Engines?

By | June 16, 2018

This is an obvious question which comes in the mind of a serious automotive buff, Why carburetors are used in petrol (or gasoline) engine and not in the diesel engine.

To understand this question, let us first fully understand, what is a carburetor.

What is carburetor

A Carburetor is a Mechanical device used to make an appropriate mixture of air and fuel for burning or combustion.

I am going to explain it in detail but only after when we learn the mechanism of combustion in Petrol (or gasoline) engine and diesel engine. lets start.

Difference in Combustion mechanism of Petrol and diesel engines

In a diesel engine the fuel is burned when fuel is injected with high pressure to the hot compressed air in the cylinder. This air reaches the engines with the help of turbocharger or natural respiration. fuel reaches the combustion chamber with the help of fuel pump. Both enter combustion chamber separately. Hence a diesel engine is also known as Compression Ignition engine. since fuel burns with the help of hot compressed air.

In petrol engine combustion takes place when a mixture of air and fuel gets spark from spark plug (spark initiates fuel burning). This mixture of air and fuel is carburetor. Hence a petrol engine is also known as spark ignition engine, since a spark is used to burn a mixture of air and petrol (or gasoline).

you can also read a detailed comparison on spark and compression ignition engines here.

Now as we know that in a petrol engine we use mixture of air and fuel for combustion (instead of directly injecting petrol in the combustion chamber), we can now discuss function of carburetor in a petrol engine.

Functions of carburetor

  1. Carburetor prepares a mixture of air and fuel (which is suitable for combustion) for an spark ignition engine.
  2. Carburetor is also used to control the speed of the vehicle.
  3. It converts petrol into fine droplets and mixes it in air in such away that it burns smoothly in engine, without any problem.

I hope you understood the concept, why we use carburetors in petrol engine. If you have any doubts please let me know in comment section. Also feel free the share the article on your favorite social media platforms.

2 thoughts on “Why Carburetors are Used in Petrol [Not in Diesel] Engines?


    What is other option in place of si engine…. I think MPFI is used…. Please explain about… MPFI


Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.