Here are some key reasons why cars need petrol or diesel:
1. Combustion: Both petrol and diesel are hydrocarbon fuels, which means they contain carbon and hydrogen atoms. When these fuels are mixed with air and ignited inside the engine, they undergo combustion. This process releases energy in the form of heat and expanding gases.
2. Powering the Engine: The heat and expanding gases generated by combustion create pressure that drives the engine's pistons. The pistons move up and down within the engine's cylinders, converting this linear motion into rotational motion. This rotational motion is then transmitted to the wheels, propelling the car forward.
3. Fuel Injection: Most modern cars use fuel injection systems, which precisely control the amount of petrol or diesel sprayed into the engine's cylinders. This allows for optimal combustion and efficient fuel consumption.
4. Fuel Economy: The efficiency of a car's engine in converting fuel into power affects its fuel economy. Different fuels have different energy densities and combustion properties, which can impact the fuel efficiency of a vehicle.
5. Emissions: The combustion of petrol and diesel also produces exhaust gases, which may contain various pollutants such as carbon dioxide (CO2), nitrogen oxides (NOx), and particulate matter (PM). To minimize the environmental impact of these emissions, cars are equipped with emission control systems, including catalytic converters and particulate filters.
While petrol and diesel are the primary fuels used in conventional vehicles, there are ongoing efforts to develop alternative fuel technologies and vehicles. These include electric cars, hybrid cars, hydrogen-powered vehicles, and biofuel vehicles. As these technologies advance and become more accessible, they may reduce the reliance on petrol and diesel in the automotive sector.
