A petrol engine, also known as a gasoline engine, is a type of internal combustion engine that uses petrol as fuel. It operates by mixing air with petrol, which is then compressed and ignited by a spark from the spark plug. This combustion process generates power, which drives the engine's pistons and ultimately propels the vehicle. Petrol engines are commonly found in many vehicles, including cars and motorcycles. They are known for their relatively high power-to-weight ratio and smooth operation. However, they typically produce more carbon emissions compared to diesel engines, making them less environmentally friendly.