Class 5 EVS

Petrol and Diesel

Car Bus Truck

All of you must have travelled by some type of vehicles. Car, bus, jeep, truck, train, bicycle, etc. are examples of vehicles. A bicycle does not need fuel because it runs on human power. A bullock cart runs on power of animals. But other vehicles need fuel to run.

Do you know which fuel is used in a car, or in a truck? A car needs petrol as fuel. A truck needs diesel as fuel? Most of the small vehicles use petrol. For example, car, motorcycle and scooter use petrol. Big vehicles, like trucks, buses and trains use diesel as fuel. Now-a-days, cars, buses and trucks also use CNG as fuel. CNG stands for Compressed Natural Gas.


A substance which is burnt to get energy is called fuel. Petrol, diesel and kerosene are burnt to get energy. Similarly, coal, wood, cow-dung cake, dry leaves, etc. are burnt to get energy. Cow-dung cake, firewood and dry leaves are used in many homes in villages to get energy for cooking. Coal is mainly used in factories.

Sources of Coal and Petroleum

Coal and petroleum are found under the ground. They were formed millions of years ago. Coal is taken out by digging very deep in the ground. Such a place is called a mine. Many other materials are taken out from mines, such as iron, copper, gold, bauxite, etc.

Petroleum is crude oil. It is dark, thick, and sticky and it smells awful. Petroleum is cleaned or refined to get petrol and diesel. Grease, petroleum jelly, plastic, petroleum gas, etc. are also obtained from refining of petroleum.

We need to dig very deep to take out petroleum from oil well. For this, huge machines are required. In India, oil wells are found at select places, like Assam, Maharashtra and Gujarat.

What If It Finishes?

You have read that it takes millions of years to form coal and petroleum. But we are using them at great speed. A time will come when all the stock of coal and petroleum shall be finished. It is going to happen in the near future. What will happen when there will be no coal or petroleum on earth? It will be impossible to travel by cars, buses, trains and airplanes.

Harms of Burning Fuels

When a fuel is burnt, it gives off many obnoxious gases. These gases pollute our environment. Air pollution affects us badly. Many people suffer from diseases of lungs because of it. Animals and plants also suffer from bad effects of pollution.

Too Many Cars

The number of cars is increasing every day. This results in traffic jams on roads. Situation is very bad in big cities. Even small towns are suffering from traffic jams. Too many vehicles on roads is a big reason for air pollution.

What is the way out?

You may have seen that just one or two persons travelling in one car. If more and more people start traveling by bus, there will be less number of cars on the road. A bus can carry more than fifty people. If more people will start riding bicycles, it can improve the situation. A bicycle does not cause pollution because it does not run on petrol or diesel.

We also need to switch to cleaner fuel. CNG produces low level of pollution. Solar energy and wind energy are environment-friendly because they do not cause pollution. Scientists are developing new technologies so that getting solar energy and wind energy can become cheaper.