SANTA BARBARA, CA – We click the nozzle into the fueling port, start the flow of “gas” and within minutes we’ve topped off the tank and we’re back on the road. Nothing unusual here, except in this case the gas is hydrogen, the powertrain is a fuel-cell stack and the car is the ’17 Honda Clarity sedan.

You won’t see that happening in every neighborhood, not for a decade or so if prognosticators are correct, but in states like California and in the Northeast where the hydrogen-fueling infrastructure is now developing, your chances are improving daily.

That’s the long view companies like Honda are taking as they invest in a technology that’s ready for the road today, but lacks the fueling infrastructure to support widespread adoption. And while detractors might pan the zero-emission Clarity as a pie-in-the-sky, niche-market science project, naysayers can’t dispel the fact that this is an excellent car.

That’s evident during our drive into the hills above Santa Barbara where the Japanese automaker introduces its third-generation fuel-cell car to the media. Our tester is plush, featuring premium materials and upscale appointments, but what’s on the surface is a minuscule part of this car’s story.

Continuing focus on the maxim “man maximum, machine minimum,” Honda engineers have packaged the most compact and most powerful fuel-cell unit to date under the hood of an Accord-sized 5-seat sedan.

“What we want is the popularization of fuel-cell technology and these fuel-cell vehicles to a much broader market, so we want people to have everything they would expect in a sedan,” explains Stephen Ellis, manager-FCV marketing. “By packaging (the components) this way and by putting the entire powertrain under the hood, it really normalizes the car.”

Honda officials aren’t confirming future products but suggest the powertrain’s size makes it possible to install it in any of its V-6 vehicles, such as the Pilot CUV or Ridgeline pickup.

Key enablers for reducing the size and layout of the powertrain include an electric compressor to feed high-pressure air to the smaller fuel-cell stack, improved gas diffusion within the cells, better management of condensed water and more efficient cooling. 

Although 33% smaller than the previous generation fuel-cell stack, the new unit produces 103 kW, 1.5 times more than its predecessor, to drive the wheels and charge a 346V lithium-ion battery pack. Honda says at 3.1 kW/L its latest stack achieves the world’s highest output density.

Electricity from the fuel-cell stack (and battery under high loads) powers a single motor producing 174 hp and 221 lb.-ft. (300 Nm) of torque routed to the front wheels via a single-speed, direct-drive transmission.

The EPA rates the Clarity’s MPG-e at 69/67 mpg (3.4-3.5 L/100 km) city/highway and estimates maximum range at 366 miles (589 km) on 5.46 kg (12 lbs.) of compressed hydrogen gas stored at 10,000 psi (70 MPa).

The compact 114-lb. (52-kg) powertrain allows engineers to completely reconfigure the Clarity’s layout compared with the previous generation, installing the fuel-cell stack and drivetrain gear under the hood, freeing up space for the battery under the midship floor where the fuel-cell stack used to reside.

That opens up room under the back seat for a second high-pressure hydrogen tank to add range to the main tank situated behind the rear seats and between the rear wheels. Honda says the new layout allows an increase in seating from four to five passengers and gives the 4,134-lb. (1,875-kg) Clarity a 57/43 front/rear weight distribution.

From the outside, the Clarity high rear decklid echoes the Accord Crosstour in profile while its LED-heavy front end shares some styling elements with Acura’s halo NSX sports car. But the car’s aerodynamic management, including the world’s-first air ducts through the rear door panels, gives the car a distinctive and more futuristic streamliner styling.

The elegant interior, dubbed the Advanced Modern Lounge, raises the bar for alternative-powertrain vehicles. Ultrasuede trim made of recycled yarn accents the dashboard and the door panels, while leather and woodgrain trim bring natural elements to the appearance. The floating center console and horizontal layout contribute to a spacious and unique interior feel.

Rear visibility seems cramped by the high rear package shelf, but a see-through lower window (carried over from the previous Clarity) provides an unexpected extra sightline.

Instruments and gauges, along with an 8.0-in. (20-cm) center display screen, provide ample information on the fuel-cell’s generation level and the range of the vehicle, along with a meter to “coach” economical driving habits. Overall, the layout is simple and intuitive with familiar Honda switchgear and controls.

On our drive through the Southern California foothills, the Clarity offers a premium and quiet ride, atypical of eco-oriented vehicles. There’s very little noise from road, wind, tires or powertrain as the Clarity whirs on its way.

Yoshihiro Atsumi, chief engineer, says three years went into developing the Clarity’s 235/45R18 Michelin Energy Saver tire. Atsumi worked with the French tire maker to ensure the rubber would be compliant and quiet without the harsh ride typical of a low-friction tire, while maintaining good dynamic response for cornering and braking.

“It was similar to development of a tire for a sports car,” Atsumi says.

Like any torquey electrically driven powertrain, power is good at launch and delivery is smooth and strong – even capable of chirping the front tires at times. There is, however, a noticeable flat zone in mid- and higher-speed driving that leaves the driver wishing for a little more response at the expense of fuel efficiency.

That damp response is somewhat mitigated by driving the Clarity in Sport mode, which amps up accelerator response as well as regenerative braking. We’d recommend driving in that mode at all times, unless maximum driving range is your primary objective.

Our stop to add half a tank of hydrogen boosted observed range from 118 miles (190 km) to 254 miles (409 km), short of the vehicle’s EPA projected range but reasonably within the driving needs in California where there are 27 retail hydrogen-refueling outlets. Price at the pump: $16 per kilogram, with each kilogram equivalent to the mileage provided by a gallon of gasoline.

To offset worries about the cost of hydrogen, 3-year Clarity lease includes $15,000 for fuel, along with 21 days’ use of luxury vehicles (through Avis) to allay range anxiety and accommodate longer trips. The $369-per-month lease price (with $2,800 down) allows 20,000 miles (32,187 km) per year, easily within the fuel allotment.

For now, Honda is limiting availability of the Clarity FCV to California, with 100 deliveries so far and projections to lease 50-60 per month going forward. Two more Clarity models, a battery-electric and a plug-in hybrid, were unveiled at New York auto show last week and go on sale later this year. The BEV will be limited to California, but the PHEV will be sold nationwide.

“By increasing the interior space, we’re making this into a normal vehicle and bringing it to the public in greater numbers,” says Ellis. “You could say this is a zero-carbon, ultimate clean car that emits only water, but really we’re trying to move this to the next step.”

A handful of people bought the original FCX, followed by the FCX Clarity that sold in the hundreds, Ellis notes. The new Clarity is expected to sell in the thousands, he says.

“It’s the stair-step approach of aligning the vehicle volumes, vehicle features and customer acceptance with a network of stations as we move forward together,” Ellis says. “We’re really bringing this to a whole new level.” @bobgritzinger