Introduced at the 1995 Tokyo Motor Show, the Honda SSM concept car was the design study for the production S2000. The SSM (which stood for "Sports Study Model") was a rear wheel drive roadster powered by a 2.0L (122cuin) inline 4 cylinder engine. It featured a push-button starter and central division between the driver and passenger which Honda claimed to improve the vehicle's rigidity. All of the body panels were aluminium and the car had a 50/50 weight distribution.
The SSM would appear unchanged in many automotive shows for several years afterwards, hinting at the possibility of a production version. Honda later announced the production version of the SSM. Carrying on the tradition of the company's 1960s S500, S600, and S800 roadsters, the new vehicle was called the S2000.
The S2000 was introduced in 1999 for the 2000 model year and was given the chassis designation of AP1. It features a front-mid-engine, rear wheel drive layout with power being delivered by a 1,997cc (122cuin) F20C inline 4 cylinder DOHC-VTEC engine producing 240hp (179kW) at 8,300rpm and 153ft·lbf (207N·m) at 7,500rpm, though European versions were rated slightly lower at 237hp (177kW) and the Japanese models were quoted with 247hp (184kW) at 8,600rpm due to a small difference in engine compression ratio. The engine is mated to a six-speed manual transmission and Torsen limited slip differential. In part because of its high-revving nature for a car engine, the S2000 achieves the highest specific power per unit volume of any mass-produced naturally-aspirated automobile piston engine, producing 123.5hp (92kW) per liter.