Honda’s fuel cell flagship reaches its second generation, but is the world ready?

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Labelling its first hydrogen fuel cell car – the first such car made available to members of the public, no less – ‘Clarity’ in 2008 ranks among Honda’s bolder recent decisions.

Doubtless, it was plucked from the marketing ether to echo the remarkable truth of the clear, semi-clean water trickling from the model’s tailpipe; because the alternative intimation is surely a reference to the brand’s strategic foresight, and its steely eyed dedication to a zero-emissions path that leads inexorably to the moral and technological high ground.

Honda claims a world first in the application of a newly developed grade of high-tensile steel in the Clarity’s platform, as well as the use of glassfibre-reinforced plastic hybrid mouldings

There’s no small irony in option B. Despite others joining Honda on the fuel cell bandwagon, almost a decade of progress has not resulted in much more clarity than we encountered the first time around.

Hydrogen, as a viable alternative fuel, continues to promise much and deliver precious little.

As before, infrastructure – the method of conveniently refuelling a car that runs on the stuff – remains a thorny issue simultaneously pricked by a lack of willpower, interest and investment.

In London, one of the biggest, richest and most populous cities in the world, there is now a grand total of five places to pump compressed gaseous hydrogen into a fuel tank. That plainly isn’t enough.

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However, that is not Honda’s fault nor precisely its problem. After all, the second generation of the Clarity, much like the first, is not about to appear in a UK dealership with a price sticker in its window.

Instead, the car will be trialled in limited numbers as part of a continuing demonstration project as the manufacturer builds towards having electrified powertrains in two-thirds of all the cars it sells by 2025.

So why this road test?

Well, like the Toyota Mirai we tested, Honda’s latest water-emitter promises to edge the holy-grail fuel cell tech that bit closer to real-world viability, with what it claims is the longest driving range of any zero-emissions vehicle.

While that might sound like planning for a moon visit with a pogo stick jump, we indubitably need proof that the horse works before anyone commits to building the stables.

Consequently, the more persuasive the new Clarity manages to be, the clearer the future might conceivably get.


Honda Clarity FCV Fuel Cell badging

Although much has changed beneath the Clarity’s skin, the skin itself has remained familiarly unorthodox.

European efforts to slide zero-emissions technology under the comfort blanket of established styling language apparently carries no weight with the Japanese.

Opening the bonnet allows you to admire the tolerances involved: the engine bay is brimmed with fuel cell, making it impossible to see the electric motor and gearbox

The Clarity, much like the Toyota Mirai, strains hard for an ugly-duckling futurism that frumpily conveys its divergence from internal combustion. As ever, this might conceivably work in Santa Monica or Tokyo, but not so much in Solihull or Tamworth.

Of course, functionally, the Clarity is less about pleasing the eye than it is soothing the surrounding airflow.

There is an awful lot of channelling and ducting going on in the name of aerodynamic efficiency, just as the car’s shape is partly dictated by the packaging requirements of the underside. Developments made in this regard are at the vanguard of the new model’s improvements, most notably in the downsizing of the fuel cell stack, which allows it to be housed under the bonnet and not in an intrusive transmission tunnel, as it was previously.

This means that three can now sit in the back – no mean feat when there are also two hydrogen tanks and a lithium ion battery to accommodate.

The tanks are smaller in physical capacity than before but the contents are kept at twice the pressure, so they are capable of storing almost 40 percent more fuel. With the tanks in the back (under the boot floor and rear seats), the battery pack is beneath the front seats and itself produces 50 percent more output than its predecessor.

Alongside the better energy storage required for greater range, the Clarity’s energy production has been enhanced.

Condensing the size of the fuel cell stack by a third has not decreased its output. In fact, the electric power per cell has increased by 50 percent, partly thanks to the introduction of a two-stage compressor that boosts air supply by 70 percent (while being 40 percent smaller than the pump it replaces).

By delivering it more voltage, the main drive motor’s output improves, too, with peak torque now 17 percent higher, at 221lb ft, and a maximum rotational speed of 13,000rpm – the highest of any Honda fuel cell vehicle to date.

To make things even easier on the fettled high-tech, the manufacturer has sought further efficiency gains in the Clarity’s construction.

Its chassis remains bespoke and has a much higher proportion of aluminium, composites and ultra-high-tensile steel than would typically be devoted to a mainstream product.

This doesn’t prevent the car from being the best part of two tonnes, but by weighing roughly the same as the lower-powered Mirai, the Clarity can be claimed to be on the edge of the fuel cell envelope


Honda Clarity FCV interior

The challenges of finding space for hydrogen storage, a fuel cell stack, an electric motor and plenty of high-voltage power electronics has often prevented the various hydrogen fuel cell prototypes the world has already seen from being practical cars, even though many were large enough to be expected to be practical.

The Clarity goes some way to correcting that. This is a big saloon with a big cabin that’ll house four larger adults in plenty of comfort, or three kids across the back seat at a push (whereas a Toyota Mirai is a strict four-seater).

Due to the unfamiliarity, getting hydrogen into the Clarity remains a slightly user-unfriendly process involving an A4 folder full of instructions

Our tape measure put typical rear leg room (our standard benchmark of what’s left in row two when the driver’s seat is set for a metre of front leg room) at 810mm – more than you get in a BMW 5 Series or a Mercedes-Benz E-Class – and showed head room to be comparable with those cars’, too.

Boot space is more disappointing because the location of one of the hydrogen tanks means you get limited overall loading length and there’s also no seat-folding or through-loading facility. Overall space is 334 litres, and although the boot is full width and of a good depth, there isn’t room to load long items like pushchairs and suitcases longways.

If you were making an entirely typical, rational assessment of the car’s interior ambience, equipment level and material quality, you’d probably observe that a customer spending upwards of £40,000 on a saloon car has a right to expect better; but remember, this isn’t a car with a fully realised business case and nor is it the average big saloon.

Many of the car’s fixtures and fittings would certainly need a bit of a material uplift in order to cut it in the mid-sized executive class – although not all of them.

Honda is committed to the idea of environmental sustainability and has opted for an Ultrasuede trim for the dashboard and door cards. This material is made out of recycled polyester via a very energy-efficient manufacturing process and looks and feels very natural. For a Clarity owner, it would never do for a living thing to be harmed in the making of the car’s seat upholstery (synthetic leather, but pleasant enough) or its veneer (a patterned ‘rosewood’ film trim made to resemble real wood).

The veneer isn’t too convincing, but it is very much like the trim fitted by Tesla, perhaps not entirely coincidentally.

The Clarity’s glossy 8.0in touchscreen will be familiar to Honda buyers, and it transfers from other models with all its established strengths and weaknesses.

In the plus column, it’s very legible and mostly easy to use. Among the negatives, its responsiveness can be inconsistent and there isn’t a car tester alive who prefers a made-up haptic volume control to the physicality of an old-fashioned dial.

Somewhat unexpectedly, the model also features Honda’s 540W, 12-speaker Premium Audio system, although typically it’s the Fuel Cell Power Monitor at which you’ll have any spare attention directed.

The monitor displays the status of the car’s powertrain and the associated storage, with energy use being delineated as a glowing blue ball graphic that changes size according to usage.

The navigation also has the capacity to show real-time status information about the nearest hydrogen stations, although a Post-it note that reads ‘coming soon’ would suffice in most of the UK.


Honda Clarity FCV side profile

It’s very early days to have many benchmarks for production-ready fuel-cell cars but, thanks to the Toyota Mirai road test, we do have some – and so compare we must.

And although it didn’t beat the Mirai in every respect for which we recorded objective figures, the Clarity outperformed its rival in most.

The brake pedal is a little spongy, making it a bit tricky to be smooth with hard stops

Needing 9.0sec to hit 60mph from rest, the Clarity is not only almost precisely as accelerative as Honda claims, but it’s also more than a second quicker than the Toyota and about as quick as the average modern four-cylinder diesel executive saloon.

In fact, the Clarity not only neatly avoids being vulnerable to criticism for its performance, but it actually does a better job than a conventionally fuelled rival in one or two ways, too.

Because the car’s electric motor drives the wheels directly and therefore peak torque is behind you once you’re beyond around 40mph, performance feels strong at low speeds and increasingly less strong as you accelerate onwards.

But pedal response is always excellent and that makes driveability first-rate, particularly around town. There isn’t really any accelerative increment over which the Clarity is quicker than, say, a BMW 520d. (It might have been over 0-20mph, but we don’t measure that.)

But it is quicker to respond to small pedal position changes – and it’s certainly quieter than the BMW at low speeds (59dB at 30mph, although at 50mph the Mirai is even quieter).

The car sounds, for the most part, like a battery-powered EV during normal driving. Its powertrain is almost noiseless at most pedal positions, with just the faintest whir starting up when you use the last 30 percent of the accelerator pedal’s travel. It is also often present at high speed.

Our test car was fitted with Michelin CrossClimate all-weather tyres and it could be expected to run marginally more quietly, and to stop more quickly on tarmac, with a more typical road tyre.

Even so, the 48.8m stopping distance it recorded from 70mph to rest was very creditable for a car of this size and proves that Honda hasn’t sacrificed a punitive amount of outright grip in order to cut the car’s rolling resistance and to boost its cruising range. 


Honda Clarity FCV cornering

Honda’s hard engineering work has put the Clarity in a good place for this section.

Saving packaging size and weight with the avant-garde powertrain and using such an exotic mix of body materials means it could bring the car in with a kerb weight that looks entirely normal for a near-5m-long saloon, and that presumably would allow it to tune the car for any kind of dynamic character it chose.

Soft, slightly under-damped suspension clunks loudly over the transmission bumps

The one they’ve picked says everything about where they expect to ‘sell’ this car and to whom – because the Clarity feels, by and large, like a typical big, laid-back, US-market four-door to drive.

It’s comfortable, well mannered, assured and easy-going and it responds to a keener driving style much as you might expect of something built for those much more interested in driving sustainably and efficiently than with a bit of vim and vigour.

Where the car departs from that relaxed dynamic type is with a well-weighted steering wheel, with a slightly higher lateral grip level and with marginally better cornering balance than perhaps it needed.

The car doesn’t exactly carve its way through bends, rolling fairly hard, but it carries on gripping and turning at speeds well beyond your expectations, and the weight and good pace of the wheel means you can drive fairly quickly in confidence.

Of much more import is the comfort and isolation of the car’s ride,  which is good at moderate speeds and on reasonably level surfaces.

The Clarity is no limousine – there’s just a little bit too much noise and edge to the suspension to make it supremely comfy – but it’s certainly comfy around town and on the motorway.

At B-road speeds, Honda’s preference for softer chassis settings does catch up with the car, as it runs out of good close vertical body control through bumps and gulleys – and often without needing to trouble the national speed limit to do so.

Approaching a corner quickly is something a Clarity owner is only ever likely to do by mistake, you would think.

Still, should they do it — or ever need to take evasive manoeuvres at high speed — they’ll be happy to find out that their car is fairly well prepared.

The grip level is better balanced than you might expect it to be, and its adhesion to level tarmac is more than respectable. The car turns in pretty smartly, with reassuring weight in the steering, and rolls a little but not a lot.

From the apex to the exit of the corner, the car leans on its electronics quite hard in order to prevent you from upsetting the front end with too much instant electric motor torque, which, if the ESP system weren’t so effective, it would be easy to do.


Honda Clarity FCV

Short of moving to California, there is currently no way of buying a Clarity FCV.

Instead, a small fleet of cars will be operated in conjunction with the HyFive Project, a European initiative intended to spearhead the creation of a hydrogen refuelling infrastructure across the continent.

There’s only one, so little choice — but in the US, you can spec a range of stick-on body mouldings and trims. Which, of course, you shouldn’t

At the moment, with the backing of BMW, Daimler, Honda, Hyundai and Toyota, the venture is focused on creating functioning network clusters in three regions, including Greater London, which now has five pumping stations.

These are located at Teddington, Hillingdon, Hendon, Rainham and Cobham services on the M25.

That’s more than when we tested the Toyota Mirai but many fewer examples than you’d find of, say, Tesla Superchargers.

Even in California, where there are almost 30 sites open and plans for many more, the Clarity is a lease-only prospect.


4 star Honda Clarity FCV

The Toyota Mirai scored a four-star road test commendation for its boldness and significance – and four stars may be translated as ‘very good’.

Honda’s like-for-like vision for hydrogen motoring deserves greater recognition in some ways (performance, packaging, driving range) and a bit less in others.

Honda’s innovative spirit makes a fuel cell future seem more realistic

So overall, it seems fair to award it the same score, one intended to reflect the remarkable effort and commitment that has brought the Clarity this far, but also the distance it still has to go before it can be a realistic choice for most drivers.

Some of the remaining progress isn’t for Honda to make, of course.

Hydrogen refuelling infrastructure has a fraction of the UK coverage of, say, fast-charge facilities for EVs and it’ll clearly be a while longer before fuel cell technology can be cheap enough to affect people’s lives in really large numbers.

But what the Clarity does, just like the Mirai, is give you heart that it’ll happen; that the car industry is doing its bit; and that the FCVs we’ll be driving in 25 years won’t be all that different from the ones we’re driving now.

As a result of Honda’s vision, the Clarity jumps to the top of our FCV top five ahead of the Toyota Mirai, the Hyundai ix35 FCV, the Mercedes-Benz B-Class F-Cell and the Riversimple Rasa.

Honda Clarity FCV First drives