Toyota has ruled out any possibility of offering a diesel hybrid version of the Prius, at least for the foreseeable future.
While brands including Peugeot are moving ahead with diesel hybrids, for Toyota the idea will still take “many more years”, according to executive vice-president Tasatami Takimoto, the man in charge of Toyota’s R&D.
Toyota has already set a high benchmark with the new 1.8-litre petrol hybrid Prius, and it sees plug-in technology as the next ecological step.
The Japanese giant is also not such a major player with diesels, and while it did a deal with Isuzu in 2007 to develop a new aluminium-block 1.6-litre diesel, a unit that could be used to power a diesel hybrid Prius, production of that engine is not scheduled to begin until 2012 at the earliest.
Ultimately, though, the issue is cost, says Takimoto. “Actually, we already make a diesel hybrid truck in Japan,” he told Autocar, “but in order to mass-market diesel hybrids we need to make the exhaust emissions much cleaner, and that requires development.
“You have to combine this clean emissions technology with the hybrid system cost, so that means that, currently, it’s a very high-cost powertrain for us,” he added. “So for Toyota, it will take many more years.”
A plug-in hybrid version of the new Prius, with a lithium-ion battery pack, is due in Japan before the end of the year. The UK will also get to see the car, probably in 2010; Toyota may confirm that plan within the next month.
The numbers are small, though; Toyota’s aim is to do a run of 200 plug-in cars for Japan, then a further 300 for the US and Europe.