Superkart is a form of motorsport road racing that uses karts on long circuits. The most obvious difference between a superkart and most other forms of kart is that they have full aerodynamic bodykits as well as having a longer wheel base than sprint chassis and are generally raced on car circuits over 1,500 metres in length. The power unit, most often, but not exclusively two-stroke 250 cc engines, can be specially designed kart engines or production motorcycle engines with either five- or six-speed sequential manual gearboxes. Owing to their high top speed and superb cornering ability, a superkart's aerodynamic bodywork includes a front fairing, larger sidepods, and a rear wing. They use either tires and wheels and most often race on full size auto-racing circuits. The 250 cc superkarts can set faster lap times than much more expensive and technically advanced racing machines. Some British and Australian classes also include 125 cc gearbox karts. Superkarts race on "long circuits" (e.g. Silverstone, Laguna Seca, Magny-Cours). In the UK they also race on "short circuits" (e.g. Kimbolton); "short circuits" are under 1,500 metres in length. Superkarts are raced worldwide. There is a multi-event CIK-FIA European Superkart Championship (for 250 cc karts only), and there has in the past been a world championship, which was last run in 1995. Performance Powered by a two-stroke 250 cc engine producing for an overall weight including the driver of 205 kilograms (452 lb), superkarts have a power/weight ratio (including the driver) of approximately 365 W/kg (490 hp/tonne)(0.22 hp/lb), or closer to 730 W/kg (980 hp/tonne)(0.44 hp/lb) without the driver, which is about the equivalent of a midget car, or an open-wheel A1 Grand Prix car. Superkarts can accelerate from 0 to in less than 3 seconds with a top speed of . Their low weight and good downforce make for excellent cornering and braking abilities. A superkart is capable of braking from to standstill in around 2 seconds, and taking corners at nearly 3 g (30 m/s²). British superkart divisions : Division 1 is open to 250 cc twin cylinder engines with five or six speed gearboxes. Typically the karts produce and are capable of - the fastest form of kart. This formula was previously known as Formula E, which was changed to avoid confusion with the Formula E series. 250 National is for single cylinder karts with five- and six-speed boxes. Typically these karts