petrolengined

Petrolengined refers to engines that burn petrol (gasoline) to produce mechanical power, most commonly in road vehicles, motorcycles, and small machinery. Petrol engines are internal combustion engines that typically operate on a spark-ignition principle and use air-fuel mixtures drawn into a cylinder, compressed, and ignited by a spark plug. The term is widely used in British English as petrol-engined, distinguishing petrol-based propulsion from diesel or electric options.

Most petrol engines today run on the four-stroke Otto cycle, though two-stroke designs exist for lighter applications. Fuel is mixed with air in a carburettor or, increasingly, through direct fuel injection, and an ignition spark starts combustion. Early engines relied on carburettors; electronic fuel injection and advanced engine control units have improved efficiency, power, and emissions control.

Modern petrol engines balance power, efficiency, and emissions through features such as turbocharging, variable valve timing, direct injection, and advanced exhaust aftertreatment. Their energy density and relatively simple construction have supported widespread use, though gasoline engines typically produce higher CO2 emissions per kilometre than modern diesels or electrified drivelines when measured on a life-cycle basis.

Petrol engines power most passenger cars and motorcycles and remain common in small aircraft, marine applications, and portable generators. Trends include downsizing with turbochargers, direct injection, and hybridization with electric motors. Environmental considerations have driven stricter emission standards and the adoption of cleaner fuels and advanced catalysts.