The Toyota Prius is a full hybrid electric mid-size hatchback, formerly a compact sedan developed and manufactured by the Toyota Motor Corporation. The EPA and California Air Resources Board (CARB) rate the Prius as among the cleanest vehicles sold in the United States based on smog forming and toxic emissions.The Prius first went on sale in Japan in 1997, making it the first mass-produced hybrid vehicle. It was subsequently introduced worldwide in 2001. The Prius is sold in more than 70 countries and regions, with its largest markets being those of Japan and North America. In May 2008, global cumulative Prius sales reached the milestone 1 million vehicle mark, and in September 2010, the Prius reached worldwide cumulative sales of 2.0 million units. The U.S. is the largest market, with 1 million Prii sold by early April 2011, and Japan reached the 1 million mark in August 2011. Since its launch in 2009, the third-generation model has sold more than 1 million units worldwide by September 2011.
Prius is a Latin word meaning "before". According to Toyota, the name was chosen because the Prius was launched before environmental awareness became a mainstream social issue.
In February 2011, Toyota asked the public to decide on what the most proper plural form of Prius should be, with choices including Prien, Prii, Prium, Prius, or Priuses. The company says "it will use the most popular choice in its advertising" and on February 20 announced that "Prii" was the most popular choice, and the new official plural designation. In Latin prius is the neuter singular of the comparative form (prior, prior, prius) of an adjective with only comparative and superlative (the superlative being primus, prima, primum), consequently, like all 3rd declension words, the plural in Latin was priora (cf. Latin declension).
Beginning in September 2011, Toyota USA began using the following names to differentiate the original Prius from some newer members of the Prius family: the standard Prius became the Prius Liftback, the Prius v (known as the Prius α in Japan, and Prius + in Europe), the Prius Plug-in Hybrid, and the Prius c. The last two are scheduled to be available in the market in 2012.
