For future hybrids, power increases will be "primarily from the electric part" of the engine, says Hans-Peter Wandt, technology PR manager at Toyota Germany.
Combustion engine elements of next-generation Toyota hybrid engines will be smaller, while batteries -- already proven up to 300,000 kilometers in test conditions -- will become lighter and more powerful, Wandt says.
The hybrid Toyota Prius is already around 60 kilograms lighter than a diesel-engined Toyota Corolla.
Vehicles with hybrid powertrains should take over the top end of Toyota's luxury brand Lexus, says a company official. Hybrid V-8 models offering more than 400hp are already planned.
While Toyota is focusing on combining gasoline and electric propulsion technologies, it also is working on diesel hybrid technology.
Toyota believes that prices of hybrid models will be more competitive in future.
"Once particle filters and the more expensive nitrogen after-treatment systems for diesel models go into series production, our hybrid cars will no longer be more expensive than diesels," says Wandt.
Because of costs, Toyota has rejected the use of so-called supercaps, high performance condensers for fast storage and release of electrical energy that are being tested on hybrids by manufacturers such as BMW.
Says Wendt: "They should be called 'goldcaps.' They are extremely expensive for large volume production."