1997–2000 (model NHW10)
The first Prius, model NHW10, went on sale in December 1997. It was sold only in Japan, though it has been imported privately to the United Kingdom, Australia, and New Zealand. Many of these cars are now being exported as second-hand vehicles to New Zealand and other countries.
2001–2003 (model NHW11)
The 2001–2003 Prius for the United States market was powered by a 1.5-liter 4 cylinder gasoline engine, a permanent magnet AC electric motor, and a 274-volt nickel-metal hydride (Ni-MH) battery pack. The gasoline engine developed 70hp (52kW) and 82ft·lbf (111N·m) of torque. The electric motor generated a maximum of 44hp (33kW) and 258ft·lbf (350N·m) of torque. Japanese versions were less powerful.
The engine and motor power were increased over the previous model. Air conditioning and a continuously variable transmission were standard equipment.
In the United States, the NHW11 was the first Prius to be sold. The Prius was marketed between the smaller Echo and the larger Corolla. The published retail price of the car was US$19,995. The California Air Resources Board (CARB) classified the car as a Super Ultra Low Emission Vehicle (SULEV).
European sales began in September 2000.
The official launch of the Prius in Australia occurred in 2001 after the Sydney Motor Show.
2004–2009 (model NHW20)
The Prius was completely redesigned into a mid-size liftback which is between the Corolla and the Camry in size, with redistributed mechanical and interior space that significantly increased the rear-seat legroom to exceed that of many larger automobiles. The new model is 6inches (150mm) longer than the previous version. Its more aerodynamic body resulted in a drag coefficient of 0.26.
The new Hybrid Synergy Drive (HSD) uses an all-electric compressor for cooling. Combined with a smaller and lighter NiMH battery, the NHW20 is more powerful and more efficient than the NHW11. Air conditioning is now operated independently of the gasoline engine, an industry first. In the U.S., the battery pack of the 2004 Prius is warranted for 100,000miles (160,000km) or 8 years.. The warranty in California is 150,000miles (240,000km) or 10 years for the Prius and in the seven Northeastern states that have adopted the stricter California emission control standards