The new Clarity indisputably shows the potential of the design. It's a big car, a 4.9-metre-long saloon with a body made from an expensive-sounding amalgam of ultra-high tensile steel, aluminium and composite. Honda claims it as "the world's most advanced fuel cell vehicle" on the grounds that it has greatly reduced the size of every powertrain component (fuel cell stack, power electronics and electric drive motor) so that the total assembly fits under the bonnet in a space slightly smaller than the drivetrain of one of its 3.5-litre V6 models.
The Clarity has two fuel tanks - one under the rear seat, another behind it - carrying a total of 5kg of hydrogen (the same as the Mirai) and Honda claims this 1800kg car has the longest driving range of any zero-emissions vehicle so far.
The Clarity's interior is plush and quite spacious in front. Honda's claim is that this is the first five-seater fuel cell car, and it is, but we don't think the central rear-seat passenger (who must sit astride a large tunnel) would be comfortable for long. Rear seat room for the other two is quite good, without approaching the standard of the Ford Mondeo. Boot space is okay, but the floor isn't flat and the front wall is oddly shaped because of the barrel-like hydrogen tank ahead of it.
On the road, driving is very much the experience you'd associate with any well set-up electric car - same smooth and swift departure from rest, accurate accelerator responses and strong torquey power delivery (the motor has 172bhp and 221lb ft or torque) and complete absence of gear changes. As with most electric cars, there's one gear and no clutch.
As you drive, there's no sound build-up from the powertrain, just a steady hum from the new, smaller two-stage supercharged compressor, plus a distant whine when the car is slowing as the regenerative brake system charges the battery. You can increase the feeling of deceleration by thumbing a Sport button on the console, although it barely sharpens accelerator response.
Handling is neat for a big car, and the ride is flat, plush and quiet and, surprisingly, the steering isn't too light. With its size and long wheelbase, the Clarity certainly isn't a car for throwing about, but it does grip nicely on corners, maintains a neutral cornering attitude even in high-speed bends, and has strong, easily modulated brakes. In short, the serene driving experience will be familiar to those who know the Toyota Prius well, except that it is quieter and smoother still. You could easily imagine this powertrain in a Rolls-Royce.