TOCHIGI, Japan — Honda Motor Co. says it has developed the first diesel passenger car engine capable of meeting California's tough 2009 air-quality standards, one that produces almost none of the emissions that have sullied the fuel's image.
The "super-clean" diesel's emissions will be no greater than those of a gasoline engine, Honda said.
The automaker unveiled a four-cylinder engine capable of propelling an Accord sedan to speeds well in excess of 120 mph during a weekend technology demonstration at its research center in this rural town about 100 miles north of Tokyo.
Honda, the world's largest engine maker and second behind Toyota Motor Corp. in production of gasoline-electric hybrid power systems, intends to add four- and six-cylinder diesel engines to its arsenal to help set it apart from rivals.
"This is just what you'd expect from Honda," said Ron Cogan, the San Luis Obispo-based publisher of Green Car Journal.
"They were the first to meet the 1970 federal gas engine emissions without a catalyst, they had a near-zero-emissions gas engine for the Accord in the early 1990s and now they're doing it with diesels."
Honda also showed off a new version of its fuel-cell electric power system that is smaller, lighter and more powerful than the current model.
The innovations made it possible for Honda Chief Executive Takeo Fukui to promise a sleek hydrogen-powered, fuel-cell electric sports sedan by 2008. Competitors are still limited to stuffing their bulkier systems into boxy vans and sport utility vehicles.
"We are driven to improve things for our own ambition and for the sake of the world and society," Fukui said in an interview. "It also is important to take the lead so we can acquire the intellectual property rights, the patents, to these technologies. That will be very advantageous should they become the standard."
Honda said a production version of the long, low FCX concept fuel-cell sedan that it unveiled 11 months ago at the Tokyo Motor Show would be available for lease to selected government and private users in the U.S. and Japan in 2008.
During their presentation last weekend, Fukui and his engineering staff displayed a mock-up of a device that would make hydrogen from natural gas and could be leased with the FCX. Such a device may prove crucial to hydrogen's acceptance as an automotive fuel, given the billions of dollars it would take to equip the nation's filling stations with hydrogen pumps.
Honda engineers said the energy required to make hydrogen using natural gas wouldn't exceed the energy saved by the fuel -- a problem when electricity is used to power a hydrogen maker.
Other developments shown last weekend included an advanced gasoline engine that can deliver 13% better mileage than Honda's already industry-leading VTEC engines, and a flex-fuel engine capable of running on pure ethanol or any combination of ethanol and gasoline.
The company said its advanced gasoline engine could be available in high-volume vehicles such as the Odyssey minivan and the Accord and Civic sedans by 2009.
The flex-fuel engine will be launched in Brazil late this year and could migrate to the U.S. and other countries as ethanol -- an alcohol fuel widely used in Brazil, where it is distilled from sugar cane -- becomes more readily available.
The California-legal diesel is a huge step forward for Honda because the state's emission rules for diesel will remain tougher than the strict federal rules that phase in from now through 2008.
Nine other states -- accounting, with California, for more than 20% of the U.S. car market -- have adopted California standards and will ban sales of engines that can't achieve them in 2009 and beyond.
Fukui, speaking through an interpreter, said he believed that the new technologies, particularly the compact and powerful fuel-cell system and the low-emission diesel, would put Honda firmly ahead of all rivals in the race for environmental leadership.
Such a role is crucial, he said, at a time when motorists are demanding greater fuel efficiency from their cars and trucks and governments around the world are imposing ever-stiffer emission and mileage standards on automakers to help stem global warming and reduce dependence on crude oil.
Several analysts said Honda seemed well on the way to becoming the standard setter.
"Toyota has taken away the U.S. environmental crown from Honda with all the attention the Prius hybrid gets," said Anthony Pratt, powertrain analyst at J.D. Power & Associates in Westlake Village. "Now Honda wants it back."
Diesel engines typically get 25% to 30% better fuel economy than gasoline engines and produce 30% less carbon dioxide, a major contributor to the global warming that most developed nations have pledged to fight.
The engines largely have been shunned in the U.S., though, because their emissions are far dirtier than those of gasoline engines and because they have a bad image with many Americans.