100 cc - another non-gearbox class, 100 cc also was split into Heavy, Light and Junior classes, was last contested in 2002 and has since been replaced completely by Rotax Max. United States superkart classes: 250 cc Formula/E or F/E - Twin cylinder, six-speed, liquid cooled Grand Prix motorcycle engines such as the Honda RS250, Yamaha TZ250 or made for kart racing engines such as the BRC250. 250 cc Inter-Continental E or IC/E - Single cylinder, five- or six-speed, liquid cooled Grand Prix motorcycle engines. Spectacle Road & Track reports that superkarts cost between $15,000 to US$20,000 in 2005. Entries of 60 or more are common in Britain. Overtaking tends to be easy, as there is room to get past, so the races tend to be full of action. Race lengths tend to be around 20–25 miles (30–40 km), because the fuel tanks are quite small, so at most meetings that feature superkarts, the karts race is often a brief, spectacular highlight (U.S. superkart races are timed 30-minute races; pre-final on Saturday, final on Sunday). A global category, superkarts are endorsed by the FIA, and were featured as a support category to the French Formula 1 Grand Prix at Magny-Cours in 2007 where they bettered Porsche Supercup lap times. See also Kart circuits KF1, the top level of karting KF2, a KF1 feeder series KF3, a KF2 and KF1 feeder series KZ1, the fastest KZ karting racing category KZ2, the second fastest KZ karting racing category References External links Kart racing series Kart models Formula racing Motorsport categories in Australia