An Interview with the "Father" of the Prius Plug-In Hybrid

We had an interview with Yoshikazu Tanaka from TOYOTA Development Center 2, TOYOTA MOTOR CORPORATION, where the Prius Plug-In Hybrid was developed.

Q: Mr. Tanaka, could you tell us about the background of the development of the Plug-in Hybrid vehicle?

Tanaka: The Hybrid vehicle was made twice as fuel efficient as a gasoline engine car, through the practical use of a breakthrough technology which uses the engine and motor together.
Even though we can reduce gasoline consumption, with such problems as depletion of fossil fuels and our present ecological conditions, we believe it is time to explore alternate energy sources, reduce CO2 emissions, or find any cleaner methods.

With that in mind, the electric power has many merits such as reliable supply, abundant availability, low cost and no need for specialized infrastructure. Even lithium-ion batteries, when compared with liquid fuels, have the demerit of an energy density by volume of about 1/50. The challenges such as short cruising range, large number of batteries that must be carried, and high cost issues make it still difficult for full-scale use.
We believe the Plug-in Hybrid vehicle is the best way for electric cars (EV) , to be widely accepted at an early stage.

Q: What actions have you taken for full-scale use?

Tanaka: First we had to decide what the cruising range of the EV should be.
The EV cruising range was set based on driver expectation levels and the effects of improved fuel efficiency found in demonstration tests in Japan, the US and Europe starting in 2007.
At this point we have set the EV range at 23.4 km (*) and from the findings in the studies by the Ministry of Land, Infrastructure, Transport and Tourism, we know this distance is sufficient as a daily driving distance for the majority of drivers in Japan. (* EV range: JC08 Mode)

Driving distance varies depending on the driving conditions, but a range of 20 km is sufficient to cover the daily driving needs. Drivers can use the electric power to go to work or to shop, and can also enjoy longer trips on holidays with empty batteries, by switching to the conventional hybrid for driving without any cruising range worries.

Q: If you were to describe the Plug-in Hybrid vehicle in one word, what would it be?

Tanaka: Using electrical energy from external sources, the Plug-in Hybrid vehicle can be driven as an electric vehicle. The driver can enjoy both an electric car and a hybrid in one vehicle. In short, combining the merits of both an electric car and a hybrid: that’s what the Plug-in Hybrid vehicle is.

Q: What are the benefits for customers?

Tanaka: Some of the actual reactions from drivers have been: "Right now I feel quite proud of myself for not putting out CO2 from driving with electricity" or, "There is satisfaction in doing something good for the earth."

Q: From your point of view as the developer, what kind of person would you like to see driving the Plug-in Hybrid vehicle?

Tanaka: I would very much like a driver who knows the environmental performance of the conventional Prius to experience an even better drive with the Plug-in Hybrid vehicle. Please participate in test-driving opportunities of the Plug-in Hybrid vehicle at various events.