Honda readies volley of new drivetrain tech

UTSUNOMIYA, Japan -- Honda Motor Co. is about to unleash a new round of powertrain technologies that aim to boost fuel economy and performance while burnishing the company’s reputation for innovation.

The systems range from a new-generation plug-in hybrid powertrain and 10-speed automatic transmission to a lean-combustion cycle that targets ultrahigh thermal efficiency.

They also include the company’s next hydrogen fuel cell sedan. And engineers even dangled the possibility of an all-wheel-drive, all-electric sports car, based on a Pikes Peak-climbing prototype. The rollout will unfold over the next five years.

Honda unveiled the technologies at its global r&d center in eastern Japan on Monday ahead of the Tokyo Motor Show.

“We’ve added a new lineup to expand our formation,” said Keiji Ohtsu, Honda’s chief officer for technology strategy.

The multipronged attack builds on the Earth Dreams family of powertrains Honda began deploying to the market in late 2012.

That makeover started with new naturally aspirated, direct-injection engines and continuously variable transmissions. Honda now is amplifying that lineup with turbocharged engines and more performance-oriented dual-clutch transmissions.

Next come more exotic technologies that enter new territory.

Plug-in promise

It starts with the hydrogen fuel cell vehicle debuting at this week’s Tokyo Motor Show and going on sale early next year.

The zero-emission, five-seat sedan succeeds the Clarity from 2008 and foreshadows the long-term direction of Honda’s powertrain strategy, executives said.

Honda said it reduced the size of the new fuel cell stack by a third, from its previous-generation technology, so that it is about as big as a 3.5-liter V-6 gasoline engine. The stack now fits under the car’s hood rather than in the center console area of the earlier Clarity.

That will enable Honda to deploy the powerplant in various vehicle types, which will help popularize the technology. Placement of the entire stack under the hood also allowed Honda to free up cabin space and squeeze in the fifth seat.

Looking further ahead, Honda is also cooperating with General Motors to develop a next-generation fuel cell system for deployment in additional vehicles around 2020.

Honda aims to wring the most from its costly investment in the FCV by using the same platform to underpin a new plug-in hybrid vehicle, Ohtsu said. That car is expected around 2018.

The plug-in will deliver at least three times the 13-miles, electric-only range of Honda’s latest plug-in, a gasoline-electric Accord. It also will allow for extended EV-mode driving on highways.

The car mates a 130-kilowatt motor and lithium ion battery to a four-cylinder engine with a displacement of less than 1.8 liters, engineers said. The Accord Plug-In had a 2.0-liter and was dropped by Honda in the U.S. for the 2015 model year.

The next plug-in will eke extra EV range through a new lithium ion battery that boosts energy density by half, said Hideharu Takemoto, a chief engineer of electrified drivetrains.

Part of the improvement came through new cathode chemistry.

10-speed

Also on tap: a new 10-speed planetary automatic transmission for front-wheel-drive vehicles, a gearbox Honda calls a world’s first. That transmission will be introduced in the “near future,” Ohtsu said. He declined to give a specific timeline.

It is expected to be used in large vehicles such as the Acura RLX and Honda Odyssey, but plans have not been finalized.

Honda will build the 10-speed in-house, and it will replace Honda’s six-speed automatic for 3.5-liter, V-6 engines.

The 10-speed is as compact as the six-speed, making it easily deployable across a wide range of vehicles, Ohtsu added.

It will boost fuel economy by at least 6 percent over the six-speed and deliver a 14 percent improvement in acceleration, Honda said. Shifting will be 30 percent faster.

Engine evolution

Honda is reaching diminishing returns on improving fuel economy by adding more gears or bolting on turbochargers.

And that is why it also is targeting improved combustion.

Honda’s goal is a next-generation internal combustion engine that achieves thermal efficiency rates of 50 percent.

Higher efficiency means more energy from internal combustion is captured to power the wheels and less is lost through heat.

Honda’s best engines today fall just shy of 40 percent.

The gambit: A new technology Honda calls Homogeneous Lean Charge Spark Ignition, or HLSI. It improves thermal efficiency while lowering the combustion temperature to produce lower emissions of nitrogen oxides. Honda aims to deploy it by around 2020.

Engineers boost cylinder inflows for more fuel-air turbulence and then set off the mix with a higher-energy spark.

‘Tesla killer’

Finally, Honda is dabbling with an awd EV layout that delivers high-torque acceleration and torque-vectoring on all four wheels for extra-precise handling.

A group of young engineers spearheaded the project as an exercise to build a car to compete in the race up Pikes Peak in Colorado. They modified a CR-Z compact sporty hybrid hatchback for the job and equipped it with motors similar to the two front motors to be deployed in the upcoming NSX sports car.

After competing up the mountain, Honda is now considering possible production-vehicle applications, said Yutaka Horiuchi, the project’s chief engineer. Vehicles using the layout likely would need to be large and high end to justify the system’s cost, he said. He suggested Tesla as a possible future rival.

Joked Horiuchi: “This is our Tesla killer.”