We don't know what the next-generation Toyota Prius will look like. But, thanks to a recent speech by Satoshi Ogiso, now a managing officer at Toyota, who was involved in the development of the first Prius, we do know something about how it will be powered.
According to Ogiso, it will mark the arrival of a new and improved family of hybrid powertrains that will deliver significantly improved fuel economy in a more compact package that is lighter in weight and lower in cost.
To do so will require major advances in each of battery, electric motor and gasoline-engine technologies, he explained.
"Our next generation of hybrids will feature improved batteries with higher energy density; that is, the relationship between the battery’s output and dimensions," said Ogiso.
To that end, Toyota has stepped up research, development and production capacity on both nickel-metal hydride and lithium-ion batteries. In addition, the company has ramped up development on new battery technologies such as solid state and lithium air, as well as new chemistries beyond lithium, such as magnesium and other low valence materials.
The next-generation Prius will combine advanced battery technologies with new electric motors that are smaller in size, and feature improved power density. While the current Prius motor has four times the power density of the first, he said, power density of the next-generation model will be even gtreater.
Equally important in the quest for overall fuel economy is the gasoline engine and its thermal efficiency. The current generation Prius gasoline-engine has a thermal efficiency of 38.5% according to Ogiso – very high by most standards.
But the new engine in the next Prius will be more than 40%-efficient he said – a world's-best figure
In its three generations so far, the Prius's fuel economy has improved by about 10, on average, with each generation. While he stopped short of declaring a similar improvement for the next-generation Prius, he stated that, "we are very motivated to beat our record."
To complement the gains in powertrain development the next Prius will feature the Toyota New Global Architecture (TNGA), which is said to have a lower centre of gravity and increased structural rigidity.
The net results, Ogiso said, are beneficial gains in ride-and-handlng, agility and aerodynamics. In addition, the interior will be roomier with refinements in design, layout and ease of operation, as well as introducing key advanced safety technologies.
The next-generation Prius plug-in is being developed in parallel with the new Prius and will address Prius PHV owners' requests for additional all-electric range, he revealed.
In addition, he said that Toyota is developing a new wireless/inductive charging system that produces resonance between an on-floor coil and an onboard coil to recharge the battery without the fuss of a cable.
Verification of that system is scheduled to begin in Japan, the U.S, and Europe in 2014.