Karts are usually no bigger than is needed to mount a seat for the driver and a small engine, most commonly a two-stroke engine. Most karts have engines ranging from 5 horsepower Briggs and Straton lawnmower engines to 125 cc motocross engines, producing around 35 horsepower. Karts typically have no suspension other than that provided by the flexibility of the tires and chassis flex, nor do they have a differential. Recreational karts have no gearbox, while more serious kart racers prefer shifter karts, which generally have a six-speed gearbox and a clutch. Shifter kart engine capacities usually range from 60 cc to 250 cc and in some less common karts, even bigger.
Kart racing is usually used as a low-cost and relatively safe way to introduce drivers to motor racing. Many people associate it with yound drivers, but adults are also very active in karting. Karting is considered the first step in any serious racer's career. It prepares the driver for high-speed wheel-to-wheel racing by developing quick reflexes, reactions, car control, precision, and decision-making skills.
As well as "serious" competitive kart racing, many commercial enterprises offer casual hire of karts. Such karts are usually powered by small, detuned four-stroke engines and are far slower than the fully-fledged competitive versions.
A popular video game rendition is Mario Kart.