The Hy-wire? Sounds like a circus act…
Don't be fooled. It’s a very significant bit of technology. When General Motors unveiled AUTOnomy at the Detroit Motor Show five years ago, the oddly compelling hydrogen-powered chassis that looked more like an overblown and high-tech skateboard than the saviour of the motor industry, was seen as something as a watershed moment. Why? Because the biggest car maker in the world was sticking its flag deep into the unknown world of hydrogen power.
It certainly doesn't look American
The Hy-wire is bit of an international playboy. While body and chassis were developed and engineered in America, the fuel cell – the same that’s found in the Vauxhall Zafira-based HydroGen3 – comes from Germany, while the styling was undertaken in Italy and the drive-by-wire technology was developed by Swedish electronic giant SKF Group. And the development all took place using internet links rather than face-to-face meetings, in keeping with the car’s advanced technology. Much more carbon friendly.
Explain this drive-by-wire nonsense…
The Hy-wire employs GM’s new X-Drive – an aeronautical-inspired drive-by-wire system that does away with pedals and steering columns. You’re faced with a simple butterfly-shaped control with two sliding and twisting grips on either side of a monitor that displays key car data. To accelerate, simply twist the right-hand grip away from you, motorbike throttle style. To brake, turn the grip towards you. To steer you slide the grips up or down. It sounds counter-intuitive but like operating that odd Segway contraption, it becomes second nature after 10 minutes. And with only a portable and easily packaged set of control links, the Hy-wire shortcuts the engineering problems of developing right and left-hand drive variants - the X-drive controller shuttles easily from side-to-side on a horizontal bar that stretches across the full width of the vehicle.
And how does that skateboard thingy work then?
The base structure is an extruded aluminium skeleton just under a foot thick. At the rear sits the 125bhp fuel cell stack which is actually 200 single cells working together. In the middle sit three high-pressure 350-bar cylindrical hydrogen fuel tanks, and the nose section houses a compact 80bhp three-phase electrical engine. At a high 12,000rpm, the brushless unit develops 160lb ft of torque and this is fed through to the wheels. And the fibreglass body is attached to the whole structure using 10 fastening points and just one electrical link between chassis and body. Despite the alu-intensive chassis, the GM weighs in at a chunky 1900kg. But almost all of that sits low in the chassis to benefit ride and handling.
What’s it like to drive?
Silent and surprisingly brisk. Because the engine runs via a single-stage planetary gear with a transmission ratio of 8.7:1, the maximum theoretical torque available at the twist of that wheel grip is a mighty 1392lb ft. The result is a surprisingly – and engagingly – rapid car that hauls the road in with an insatiable and whispering appetite. Being a zillion pound prototype, GM suits weren’t exactly happy about us rocketing along, but even at slower speeds the advantage of having all that weight slung low down can be felt with little roll through corners and, bearing in mind its one-off status and huge 22-inch wheels, a surprisingly compliant ride.
What’s it’s like inside?
Vast, in a word. Unhindered by a car’s normal design constraints, Bertone has created a spacious and accommodating cabin, a feeling exacerbated by the suicide rear doors, goldfish bowl windscreen, uncluttered dash design and the transparent panels in the nose and tail. You can look right through this car, and you initially feel rather exposed on the go because you can see the road, unhindered by pedals, pass below you. But after a few trips around the block you forget about the high-tech gubbins beneath you and enjoy the plush cabin.
There’s no denying the attraction and appeal of the Hy-wire. But the problem with hydrogen-powered cars has never been their design or engineering – it’s hydrogen itself. Hydrogen power may be clean and environmentally friendly but it comes with a lot of baggage. For a start, introducing a global hydrogen supply network would call for a barely conceivable amount of investment. Do existing energy companies take the first step and create the supply chain, or do car manufacturers start producing hydrogen-powered vehicles on a commercial level and create the demand for the hydrogen? It’s the multi-billion pound question, and at the moment no one is rushing forward with their chequebooks. And let’s not forget that it’s a highly unstable, corrosive and inflammable gas that would need to be stored at very high pressure, or the fact that fuel cell stacks are incredibly expensive. They make a lot of sense when used on a large scale to provide the power for a hospital or office block for example, but to produce them on the scale demanded by the automotive industry calls for vast levels of investment. Which explains why five years after the Hy-wire’s debut, we’re still chugging around in petrol and diesel cars.