Honda is developing its new plug-in hybrid technology for mid to large cars, a strategy that might mean the petrol-electric drivetrain first appears in the next-generation Accord sedan.
The Japanese company has confirmed that its first plug-in hybrid vehicle will be launched in Japan and the United States in 2012.
It will have a range of 60km on electricity before the petrol engine kicks in. General Motors' Volt uses a similar system: its electric motor gives the Volt a range of 64km before the car's 1.4-litre fires to extend the range to upwards of 500km.
Honda president and CEO Takanobu Ito said the development of the plug-in hybrid was part of the company's strategy to push to the front of a race by global carmakers to develop more fuel-efficient cars.
"Honda will fulfil customer demand more precisely by developing and adopting multiple hybrid systems that are appropriate for vehicles of different sizes and use."
The new plug-in hybrid powertrain for larger cars is being developed in parallel with a full-electric vehicle that makes use of Honda's extensive development work on fuel-cell prototypes. Both technologies are a departure for Honda. It has preferred the simpler and cheaper "mild hybrid" Integrated Motor Assist (IMA) technology to the Prius-style "power-split hybrid" or full "series hybrid" as employed on GM's Volt.
In Honda IMA hybrids, an electric motor/generator is sandwiched between the petrol engine and transmission to assist acceleration and thus reduce fuel consumption.
Under deceleration, the IMA unit provides regenerative braking, returning electricity to the nickel-metal hydride battery pack.
This system currently propels Honda's Insight, Civic Hybrid, CR-Z and the forthcoming Jazz Hybrid. The Insight is expected in New Zealand later in the year.
Although details of the new plug-in hybrid vehicle remain under wraps, Ito said the vehicle would be capable of trips of up to 60km using the electric motor alone, without the need for the petrol engine.
Toyota's new Prius Plug-In, which is being trialled in New Zealand ahead of a sales launch next year in Japan and the United States, offers a full-electric range of just 20km before the 1.8-litre petrol engine starts.
Both the Volt and Prius Plug-In are expected to hit New Zealand showrooms in 2012.
Honda and Toyota have been the only two carmakers to offer petrol-electric cars during the past decade.
Honda lost a few years in the green-car race after deciding in late 2008 to drop the development of clean diesel engines to power its bigger cars, for a new, more powerful hybrid system. It is looking to raise the ratio of hybrid vehicles to 10 per cent or more of total production by 2015, from 5-6 per cent, rapidly boosting the percentage after 2015.
Honda had so far only announced plans to sell a battery-run electric car in the US simply to meet legal requirements in California, arguing their batteries were too expensive to be practical.
Honda has been a strong proponent of hydrogen fuel-cell cars as the best zero-emission alternative to today's combustion engine cars, but their infrastructure hurdles are even bigger than for plug-in vehicles.
As part of its aim to reduce carbon dioxide emissions across all its products, Honda said it was also developing a new two-wheeler to compete in China's massive electric bicycle market, estimated at more than 20 million units a year.
Among other steps to lower carbon dioxide emissions, Honda plans to launch a new small diesel model in Europe in 2012.