OYAMA, Japan — It is a familiar racetrack scene. But this time, Toyota has a new twist.

The automaker’s petrol- head president, Akio Toyoda, is barreling down the straight at Fuji Speedway in a souped-up Toyota racer, clocking 140 mph with thunderous engine growls and bone-rattling vibrations before slamming on the brakes to tuck into the corner.

His tire-smoking No. 32 race-spec Corolla looks, sounds and drives like any other car in the field. But there is one important, invisible difference. While the rival racers are all burning gasoline, Toyoda’s engine is powered by hydrogen — and it is churning out virtually no carbon dioxide.

Note the distinction: It’s not a silent hydrogen “fuel cell” under the hood, but a freshly minted “hydrogen-burning” three- banger.

The engine is still just a prototype, but Toyoda believes it holds big promise for his company, for the industry and for carbon neutrality in a world seemingly gone gaga over full-electric vehicles.

His message here was as loud as the engine’s redline wail: Policymakers should butt out of dictating battery-electric vehicles, because myriad other technologies — including combustion — can be green and clean.

“The ultimate goal is carbon neutrality,” Toyoda said after completing the Fuji Super Tec 24-hour endurance race, where he rotated behind the wheel with five other drivers. “It shouldn’t be about rejecting hybrids and gasoline cars and only selling fuel cells and battery-electric cars. We want to expand the choices available in the path to carbon neutrality. This is the first step.”

To skeptics, Toyoda’s May 22-23 run in the foothills of Mount Fuji may seem like a desperate last stand for a technology on deathwatch. Or a fig leaf for Toyota’s slow, seemingly reluctant shift into battery-electrics, as competitors at home and abroad invest billions into EV-only futures.

But seen another way, Toyota Motor Corp. is opening a new front in the war on greenhouse gas emissions. Toyota believes technological breakthroughs, such as this one, can give internal combustion a new lease on life — saving jobs as well as the environment. It is a debate over the best road to net-zero carbon, with a pushback against government mandates that reflexively phase out internal combustion in favor of EVs.

“Toyota isn’t doing this because it’s behind in EVs,” said Takaki Nakanishi, head auto analyst at the Nakanishi Research Institute. “Toyota’s doing this to save Japan’s auto industry and its domestic supply chain. This is a performance by Toyoda to influence policy in a better direction.”

Development of the new Toyota engine began in secret in 2016, and it was first shown to Toyoda in December. It is still a long way from mass production; the automaker has no concrete timeline.

One rationale behind debuting the engine in the Corolla H2 concept at Fuji was showmanship — Toyoda is so confident in the new direction that the 65-year-old president decided to unveil the engine by driving it himself in a 24-hour, all-night race, declaring its viability in a high-speed endurance setting.

“Without a doubt, bringing the car into this severe environment will speed up development,” said Koji Sato, president of Toyota’s Gazoo Racing Co. and global head of Lexus.

Simply completing the grueling race was deemed a victory, even though the car spent 12 of the 24 hours in the pits, including four hours refueling. It finished 49th in the 51-car mixed-class field, though it entered in a special class for developmental cars and winning wasn’t the objective.

Japanese journalists billed it as a “historic” run and cheered Toyoda and his team with rousing applause at a post-race press conference in pit row.

But commercialization of hydrogen engines faces many of the same roadblocks as hydrogen fuel cells. Pressurized hydrogen gas is expensive and the refueling infrastructure scant. And its carbon-fiber on-board fuel tanks are heavy and costly.

But Toyota is playing the long game, eyeing the Japanese government’s goal of nationwide carbon neutrality in 2050.

“We still have 30 years,” Toyoda said. “Thirty years ago, we didn’t even have hybrids or fuel cell vehicles. … It’s not a good idea to narrow down our options now.”

Toyoda has reasons, both pragmatic and patriotic, for championing internal combustion.

As the head of Toyota, he can fully leverage the company’s massive $10 billion R&D war chest to spread bets across a range of tomorrow’s tech. Toyoda also wants a longer life span for the hybrid systems into which his company has sunk billions of dollars.

Meanwhile, as head of the Japan Automobile Manufacturers Association — a post he has held since 2018 — Toyoda wants a smooth transition into the electrification age for Japan’s automakers and suppliers that are still wrapped up in internal combustion.

Toyoda notes that some 10,000 components go into an engine system — roughly a third of all of a vehicle’s parts. EVs not only have fewer parts, they require fewer work hours to build. The concern is that a wholesale shift to EVs could wipe out swaths of suppliers and their jobs. That, in turn, could undermine the country’s entire supply chain.

The rush to BEVs is partly a response to government goals for net-zero greenhouse gas emissions. That is an objective pursued by the European Union, China and South Korea among other countries. Japan pledged to become a net zero-emissions society by 2050 and plans to phase out the sale of new vehicles powered solely by gasoline by the mid-2030s.

Toyoda says knee-jerk reactions are shortsighted.

“What Japan should do first is add technological options. I think regulations and legislation come next,” he said at a recent event, wearing his manufacturers association chairman hat.

“Engineers and workers involved in engine manufacturing would lose their jobs. … We need to be practical and sustainable.”

At risk are jobs tied to everything from piston rings, ignition coils and spark plugs to gearboxes and turbochargers.

This month, Daimler CEO Ola Källenius joined the chorus of concern about the switch to EVs, telling Reuters, “We have to have an honest conversation about jobs.”

Honda, Jaguar, General Motors, Ford, Mini and Volvo are among those making their portfolios heavily, if not entirely, EV-oriented. Honda plans to completely drop combustion engines from all new-vehicle sales by 2040.

Toyota, by contrast, is taking a diversified approach. The automaker wants to sell 8 million electrified vehicles by 2030, but only 2 million will be full electrics or fuel cells. Among other future technologies, Toyoda also is pitching electrofuels as a way to deliver cleaner internal combustion.

Hydrogen-combustion engines could ease the transition by piggybacking on existing technology. For the race, Toyota engineers modified the 1.6-liter, three-cylinder turbocharged engine used in the GR Yaris. They added a high-pressure injection system from Denso Corp., adjusted the spark plugs, strapped on four hydrogen tanks and connected it all with feeder lines.

Toyota says the system is an improvement over earlier attempts at hydrogen combustion, delivering output powerful enough to compete in racing. Previous industry attempts at hydrogen engines typically fell short on horsepower. Toyota’s race engine had to have its output tuned down from the GR Yaris’ 268 hp, to cope with heat management issues.

Improving performance will hinge on better heat management and injection technologies. Fuel economy may also be an issue. Toyota’s thirsty race car had to pit 35 times, mostly for fuel. Still, Toyota’s effort may already be attracting converts.

Mazda developed hydrogen-burning versions of its trademark rotary engine in the 1990s and early 2000s. It was used in limited lease fleets of the Premacy multipurpose vehicle and RX-8 sports car. But the program faded away when Mazda shifted focus to its Skyactiv line of gasoline and diesel engines and electrification. Ahead of the Fuji Speedway race, however, Mazda CEO Akira Marumoto signaled support for possibly reviving the technology.

“To reduce carbon dioxide emissions, it is necessary to have a multi-solution, using all kinds of electrification and carbon-neutral technologies,” Marumoto said. “We have the hydrogen engine as one such solution. We have already verified that the rotary engine and hydrogen are highly compatible.

“As such,” he added, “we would like to secure our hydrogen engine technology as one solution.”

Naoto Okamura contributed to this report.