Jun 16, 2008

2008 Honda FCX Clarity Hydrogen Car Test Drive: Road-Ready Fuel-Cell Fun

The name says it all: Amidst the clatter of alternative-fuel buzzwords, pilot programs and experimental prototypes, the Honda FCX Clarity is on a deliberate path to production, joining the horse race to become the world’s first true fuel-cell vehicle. Like General Motors’ Project Driveway, in which GM will lease 100 limited-production Chevy Equinox Fuel Cell vehicles to select customers, Honda will keep the Clarity’s distribution small—an undisclosed number of vehicles will head to pre-selected Southern Californians next spring, with a three-year lease at $600 per month. But the difference here is that the Clarity is a unique model expressly designed from the beginning to be a road-ready fuel-cell ride.

Honda released its first fuel-cell prototype in 1999 as the FCX-V2, which evolved into the FCX by 2005. Taller, narrower and 150 pounds heavier than the Clarity, the FCX felt as dense as a cannonball, drove like a golf cart and had the curb appeal of a kitchen appliance. The hydrogen fuel stack was eventually refined into a smaller, lighter, more powerful unit that currently produces 100 kW. The new vertical hydrogen fuel cell utilizes an aromatic electrolytic membrane and wave flow channel separators for greater efficiency, and works in concert with a lithium-ion battery pack that’s 40 percent lighter and 50 percent more compact than the previous version—not to mention more energy dense. The 12,500-rpm brushless electric motor not only provides acceleration but also becomes a power generator during deceleration. As expected, regenerative braking also serves to recharge the battery. The FCX Clarity utilizes 74 percent fewer parts than its boxy predecessor, and its aluminum and carbon resin hydrogen tank stores H2 gas at 5000 psi.

The new model was unveiled at the 2007 Los Angeles Auto Show, and is built on what Honda is calling a V Flow platform configured to optimize crash safety while coping with the unique structural demands of fuel-cell components. Because no internal combustion engine resides under the hood, overhangs are short and cabin space expanded. Honda doesn’t publish aerodynamic drag coefficient figures, but the Clarity’s flat underbody and tapered shapes are as sleek as you’d expect from a purpose built, environmentally responsible sedan. Steel and aluminum body panels reflect a realistic attitude toward cost control, and overall vehicle curb weight is 3582 pounds.

Silence permeates the cabin until you turne the key and shift the dash-mounted joystick is shifted into the “D” position. As the car accelerates, a hushed but high-pitched whine is accompanied by a variety of unusual whirs from the rear of the passenger compartment. These auditory visitations are neither loud nor obtrusive, but rather foreign sounding for folks accustomed to the soundtrack of internal combustion engines. At highway speeds, the Clarity rides with impressive sound insulation, and fuel economy is represented on the instrument panel using an animated ball that expands, contracts and changes an almost iPod-like hue based on fuel efficiency. It isn’t as graphically informative as Toyota’s Hybrid Synergy Drive flowchart, but it gets the message across, with green LEDs on the left reflecting battery charge and blue LEDs on the right representing remaining H2 levels.

A coaxial, single-speed gearbox bundled with the electric motor provides smooth, seamless propulsion in concert with the fuel stack. The gradual buildup of power peaks with 134 hp and 189 lb.-ft. of torque, which is good for a top speed of 100 mph. The theoretical cruising range is 270 miles, and hydrogen refuels should take three to four minutes, Honday says. While ride quality is generally decent, the Clarity’s low rolling resistance tires and suspension damping are a bit firm. You certainly can feel what those tires are doing over all but the smoothest road surfaces. The electric steering is light and produces moderate feedback, and the brake feel is a bit springy, particularly during lower-speed city driving. An equivalent of 68 mpg is expected across city and highway driving.

Climb into a rear bucket seat and you’ll be surprised by the impressive amount of legroom, especially considering the Clarity’s exterior proportions are 4 in. shorter than a Honda Accord. A polycarbonate divider enables visibility through another window at the rear of the car that, like the Prius, helps facilitate parking. A backup camera offers further assistance when the 10 cu.-ft. trunk is filled to capacity. The front seats provide a spacious view through the large, steeply raked windshield and small A-pillar windows that dip below the beltline. The theme of three-dimensionality dominates the dashboard and instrumentation, which are sculpted into shapes that add a subtle sense of depth to the cabin. Though surfaces are upholstered using Honda Bio-Fabric (a polyester derived from corn), the interior comes across as surprisingly upscale thanks to discreet semi-matte wood trim, black lacquer and soft-touch materials. Apart from a few imperfect appliqué surfaces that reflect our test vehicle still being a prototype, the Clarity offers well thought-out ergonomics and features such as adaptive cruise control, high-definition CD audio and XM satellite radio, and individually cooled and heated seats intended to discourage A/C usage and enhance fuel efficiency.

A refueling infrastructure is, of course, the Holy Grail of hydrogen-powered vehicles. And Honda is attempting to address that immense challenge by developing a number of options to make the FCX Clarity usable in the real world. While feasibility tests are being conducted for solar panels that electrolyze water into hydrogen, the most promising advance so far is what Honda calls the Home Energy Station IV. Not only is this unit capable of converting natural gas into hydrogen fuel, it’s also designed to provide heat and electricity for homes using fuel-cell cogeneration. Though it’s still in the experimental phase, if this system eventually works as well as the FCX Clarity drives, a brave new world of alternative fuel might be as close as home. —Basem Wasef

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