(Repeats story that first ran on March 16 with no change in text.)
By Norihiko Shirouzu and Yoko Kubota
SUZUKA, Japan, March 16 (Reuters) - After a seven-year hiatus, Honda Motor Co. is returning to the F-1 circuits next year, resolving to win more races - and learn how to build "greener" cars.
Honda is particularly aiming to turn exhaust gas that is mostly wasted in F-1 or conventional cars into energy. It is technology that Honda's F-1 chief, Yasuhisa Arai, says could give Honda an edge with its mass-market cars.
Cynics aren't buying the argument that Honda wants to use the F-1 as a technology incubator. They say Honda is trying to redeem its name after being a dud on the F-1 circuits from 2000 to 2008, when it quit the world's premier motor sport.
Arai doesn't necessarily disagree with that. He says Honda wants to be as successful as it was in the late 1980s when McLaren-Honda cars, driven by the late Brazilian triple champion Ayrton Senna and French four-time champ Alain Prost, dominated the sport. In 1988, Senna and Prost together won 15 of the 16 Grand Prix races.
"There's no point in racing unless you win," Arai said, strolling around a classic Honda F-1 car circa 1964 on display during a recent F-1 fan event at the Suzuka Circuit, 50 kms (30 miles) south of Nagoya in central Japan.
"That's why we teamed up with a winning team," Arai said referring to McLaren. Honda is set to supply engines starting in 2015 to McLaren, one of the most successful teams in F-1 history.
'LABORATORY ON WHEELS'
But Honda's return to Formula One is not just about the race, either.
Honda believes the new F-1 cars, which are now required to have gasoline-electric hybrid technology, offer an opportunity to make a technology leap.
The new regulations from the F-1 governing body require teams and engine suppliers such as Renault, Ferrari and Mercedes-Benz, to use a smaller engine, enhanced by turbo-charging technology, while using braking and exhaust to re-generate energy. Teams are also being given around a third less allotment of gasoline to race, compared to the previous race rules.
The regulations came into effect with the new F-1 season that kicked off in Melbourne this weekend.
Honda is particularly interested in the new requirement to use "exhaust-energy recovery" technology. Among other possibilities, it is looking at a way to use exhaust gas to spin a turbine in the car's exhaust system to generate electricity and store it in an onboard battery. A McLaren-Honda F-1 car, starting next year, could use such regenerated energy to go faster or farther.
Honda's move reflects what Arai calls a resolve by CEO Takanobu Ito to use the sport as a "laboratory on wheels," just as originally envisioned by company founder Soichiro Honda in the 1960s.
Establishing that exhaust-energy-recovery know-how should help Honda boost the so-called thermal efficiency of an F-1 car by as much as a third, Arai said.
Even the best of today's most advanced gasoline engines use only 30 percent of the thermal energy they create by combustion. The rest is wasted during braking and leaks out through exhaust pipes as heat. Arai wants to improve that thermal efficiency to as much as 40 percent.
"There's no technology like that available today," said the 57-year-old engineer, who is also senior managing director at Honda's R&D arm. "It's highly challenging, but if achieved, it could be applied in conventional cars."
It's not always easy, however, to use racing as a technology incubator. Current and former Honda executives who spoke on condition of anonymity said two forces often collide as teams prepare for each race.
"In the boardroom, managers can say all they want about the importance of using racing as a laboratory, but once the race starts, winning it becomes the No. 1 priority," one former Honda F-1 engine designer said. "New ideas often get in the way."
Where those two forces coincide is around fuel efficiency - with Arai hoping to apply the technology developed for Formula One cars to its mass production models.
For Honda, it is also an extension of a broader effort by CEO Ito, who has held Honda's top job since 2009, to regain the edge it once had as a daring, risk-taking automaker. Toyota Motor Corp. over the past two decades has been seen as the more futuristic company. That reputation was largely due to the success of the gasoline-electric hybrid, Prius - technology that Honda failed to initially embrace fully, though the company under Ito has since adjusted its strategy.
"Inside Honda, we call the 2000s a lost decade, void of progress and impact and momentum," a senior Honda executive said.
One of the company's missteps during those years, company insiders say, was remaining in F-1 racing from 2000 through 2008, during which time Honda won just one race. At the time, the sport was paying little or no attention to advanced technology - even as consumers around the world demanded more fuel-efficient cars - and thus contributing little to the advancement of conventional cars.
Now Formula One, thanks to the new rule change, has become an "enormously challenging" battle front for new technology, Arai says. By again competing on the F-1 circuit, Honda hopes to hatch ideas that give its engines an "unknown level of fuel-efficiency," he said. (Reporting By Norihiko Shirouzu and Yoko Kubota. Additional reporting by Maki Shiraki. Editing by Bill Tarrant.)