The Toyota Prius has reached the milestone of three million units in global sales. The Prius started life as a quirky saloon in Japan back in 1997 and has grown to be the symbol of hybrid cars.

In its progress through three generations, Prius has benefited from improvements and innovations that have made it kinder to the planet, cheaper to run and more practical to live with. Official CO2 emissions figures have fallen from 114 to 89 g/km and the cost of its hybrid powertrain has been reduced by two thirds. In the process of developing the current, third generation model, Toyota filed more than 1,200 patents.

In the past two years, Prius has grown from being a single model to a family of cars. In Europe the range includes the Prius+ seven-seat MPV and Prius Plug-in. Here, we have the smaller Prius c (Toyota Aqua in Japan), while Europe gets the Yaris Hybrid.

Toyota has made hybrid a core technology and it continues to make significant investments in the tech. In the financial year ending in March 2014, Toyota is expected to spend more than 790 billion yen on R&D and facilities for developing hybrid and other cutting edge technologies, as well as strengthening development of new platforms and components.

Projects include a new 651-hectare R&D facility and a new 12-storey powertrain development and engineering building in Toyota City.