Air curtains channel air around the tires. Wheel covers deflect airflow.
WAKO, Japan — “Beautiful” the new Honda Clarity hydrogen fuel cell vehicle is not.
With its partially covered wheels, bulbous front end and a plethora of slits, vents and creases, the zero-emission car obviously is aiming for something other than good looks.
But Honda engineers and designers say there is method behind the madness of flourishes that make the Clarity the brand’s most visually jarring design since the first-generation hybrid Insight.
During a first drive of the production-version Clarity around Tokyo’s suburbs earlier this week, the sedan handled with the smooth, quiet precision of a premium car at the top of Honda’s range.
Eking every last mile from a full tank of hydrogen will be a key to the success of the Clarity, which Honda bills as the ultimate green car.
The five-seat sedan went on sale in Japan in March and arrives in the U.S. this fall. With a full tank, it can cruise almost 470 miles with water vapor as its only emissions.
Honda won’t disclose the Clarity’s drag coefficient. But Shugo Kamemoto, the assistant chief engineer in charge of aerodynamics, says it is the slickest sedan in Honda’s lineup, besting the aerodynamics of the Accord and the Civic four-door.
Covers and curtains
Like the original Honda Insight, the Clarity employs rear wheel-well covers to help deflect the airflow. But engineers trimmed the Clarity covers to tone down the unfashionable fully sheathed look.
Despite being classified a sedan, the Clarity gets a super-sloped fastback that ventures close to hatchback territory. The Clarity evokes the look of the low-selling Honda Crosstour.
The taillights have three oddly protruding lines. Although they look like they would interrupt airflow, they actually improve aerodynamics by shedding air straight off the rear, preventing it from curling behind in adverse eddies, according to Kamemoto.
To better split the wind, engineers also gave the Clarity front and rear air curtains. These tiny tunnels in the bodywork, just in front of the wheels, help channel air around the tires.
The front curtain openings are stashed under the bumper. The rear ones are far more noticeable, with jet-engine-intake styling. It is a world’s first use of such air curtains in rear-door paneling, says Ken Sahara, the car’s senior exterior designer.
They aren’t the only conspicuous holes in the sheet metal.
Perched above the front wheels are what appear to be brake vents. But the Clarity hardly needs vents to throw off brake heat. It was not designed for speed and takes about 9 seconds to accelerate from 0 to 60 mph.
The vents are emergency releases for excess hydrogen. If the fuel cell stack under the hood is damaged in a crash and begins to leak hydrogen, the vents are meant to safely disperse the gas into the environment.
The evacuation helps prevent a possibly explosive buildup of flammable hydrogen under the hood.
There is another emergency release in the rear to vent gas from hoses connected to the hydrogen tank. After a crash, that gas is released from a duct around the hydrogen fueling port.
Two fuel flaps?
The car also has two fuel ports — one on each back corner. One is for refilling the car’s two hydrogen tanks. The other is actually an electrical outlet that allows owners to use the Clarity as a portable generator to power everything from barbecue grills to homes hit by blackouts.
Inside, the Clarity has an upscale ambience. Well-executed faux wood paneling, Ultrasuede trim and padding and a minimalistic layout contribute to a serene feel in a spacious cabin offering room on par with the Acura RLX. The ride is quiet, the steering deliberate and the handling smooth.
Thanks to its 130-kilowatt electric motor, the Clarity delivers peppy low-end torque for exhilarating acceleration.
But Honda clearly does not envision the Clarity selling in large numbers.
The company is building the car at the rate of just two per day. It aims to lease just 200 in Japan by the spring of 2017.
Chief Engineer Kiyoshi Shim-izu says Honda aims to deliver only another 200 in the U.S. in the first year after it lands there.