This exotic vehicle's trump card isn't maximum speed, but minimum refuelling
Super-economical 'Supercar' PHOTO: TORQUE

This coupe doesn't have 600bhp, nor will it hit 300km/h. It doesn't have
brake discs the size of dinner plates, and its exhaust will never howl. But this diminutive silver machine is every inch a supercar, from its high-tech construction to its sky-high fuel economy of 111
kilometres per litre.

In 1998, Ferdinand Piech (then head honcho of Volkswagen) ordered his
engineers to develop a car that needs just one litre of fuel to travel a hundred kilometres, i.e. 100km per litre. The end result was a carbon fibre-bodied, single-cylinder, tandem two-seater. Piech climbed behind the wheel of this prototype for his last public appearance as VW chairman in 2002 and drove from his office in Wolfsburg to the shareholders' meeting in Hamburg. It was raining that day and he managed to beat his own target for the car, averaging 110km per litre.

In 2009, Martin Winterkorn (successor to Piech) and his head of Research
and Development, Ulrich Hackenberg, resurrected the project - a production car that could achieve the 1L/100km target. After another "one-litre" prototype (the 2-cylinder hybrid L1) had come and gone, the XL1 was finally born.

It's 3888mm long and just 1153mm high (lower than a Lambo Gallardo), with a drag coefficient of 0.189, which makes it the most "slippery" car in the world. The XL1 is also the world's lightest hybrid vehicle, weighing merely 795kg (without driver or diesel fuel). Its CFRP (carbon fibre reinforced plastic) body weighs just 230kg. At the heart of the XL1's hybrid drivetrain is, quite literally, half a 1.6-litre turbo-diesel 4-cylinder. Made of aluminium, with plasma-sprayed cylinder walls and a balance shaft (to reduce vibrations), this two-piston motor produces 48bhp and 120Nm. Supporting it is a 27bhp/140Nm electric motor with a plug-in
hybrid system, using a thin motor/starter and a 5.5kWh lithium-ion battery. The transmission is a magnesium-alloy, 7-speed dual-clutch unit driving the rear wheels.

Every component of the XL1 was designed with a single focus: to be as
energy-efficient as possible. For instance, the wind-cheating shape of the car was modelled after that of a dolphin, and there are no wing mirrors to disrupt the air flow - in their place are small cameras which send live images of the surroundings behind the car to two displays at the front
edge of the inside door panels.

And there's more… LED headlights and tail-lights, carbon-ceramic brakes,
electrically driven air-conditioning, a flat underbody and scratch-resistant
polycarbonate windows (that weigh 33 per cent less than regular glass windows). Even the anti-roll bars are made of carbon fibre, while the wheels are lightweight magnesium alloy. The rear wheels are also fully covered to prevent air turbulence.

It's pretty obvious that the people behind the XL1 have thought of almost
everything. In the event of the car rolling over as a result of an accident, the "wing" doors can be released by deploying their explosive hinge bolts.

So, how does the XL1 drive? Our test route was a short 30-minute jaunt
through narrow town streets, coupled with a sprinkling of winding country roads and a short blast down the autobahn. To get moving, a firm prod of the throttle pedal is needed, after which the car whirs "away". In normal operation, the XL1 functions as an electric vehicle, with its 0.8-litre TDI engine cutting in only when the accelerator is floored or when the speedometer exceeds 100km/h.
The engine's activation is obvious, too, as the motor sits right behind the seats and sounds like a cross between a grass mower and a hand-held drill.

Through town and at low speeds, the bespoke Michelin tyres crash through potholes and transmit every bit of vibration into the cabin, and the unassisted steering feels rather strange, being vague around the centre position. On the flip side, the engineers have down a great job of combining energy regeneration and friction braking in that left pedal.

Once out of the cramped confines of town, the XL1 calms down considerably. While doing zero to 100km/h in 12.7 seconds reads more like a statistic from the brochure of a boring family saloon, the XL1's engine and electric motor are able to handle even the most urgent of overtaking manoeuvres. Torque, by the way, is limited to preserve the delicate 7-speed gearbox, and top speed is restricted to 160km/h. That's probably as fast as you would ever want to drive on those skinny tyres.

At speed, the suspension feels a lot less fussy and tames the roads better. The noise coming from the bitumen is also more muted. Likewise, the steering feel improves dramatically as the speed climbs, and there is a lot of feedback. However, the steering wheel loads up alarmingly when taking tight corners at speed, which is a shame as the XL1 otherwise handles like a low-slung coupe should.

The electric-only driving mode lasts 50km or until the juice in the battery falls to 14 per cent. When that happens, the engine starts to maintain the charge and propel the vehicle, but it will not fully recharge the battery. To do so, you have to plug the car's "power point" into a socket at home. Recharging takes around an hour.

While the quoted fuel consumption figure is 0.9L per 100km, the VW staffer with me throughout the test drive clarified that the actual consumption is 0.83L per 100km (European Union laws require that the number in the first decimal place be rounded up to the next highest fi gure, regardless of the decimal number). Given the XL1's tiny 10-litre fuel tank, this gives an official range of over 500 kilometres.

It isn't 1110 kilometres (111km/L multiplied by 10 litres) because the
New European Driving Cycle, or NEDC, measures the mileage of a plug-in hybrid differently. NEDC calculations are based on the assumption that the car is run on its battery power alone until it runs out of energy, after which the combustion engine takes over till it runs out of fuel, and the amount of fuel used is then divided over the whole distance travelled to arrive at the NEDC combined fuel consumption, which is 0.9L/100km in the case of the XL1.

The highlight of the cabin is its seating arrangement. The two thinly padded, ultra-light seats (each is half the weight of a conventional seat) are positioned almost side-by-side, with the one for the passenger placed slightly aft of the driver's. This clever idea ensures that both occupants have adequate shoulder room, without needing the car to be any wider. This interior layout is much better than the original tandem design. My passenger (also a six-footer like me) and I had no trouble finding a really comfortable sitting position. There's even space for 120 litres of cargo under the boot, behind the engine.

The largely black fascia looks rather sombre, but the cabin is delightfully simple and unadorned. There's an instrument binnacle from the Up supermini, a selection of Polo and Up switches on the centre console, and a prominent Garmin display giving navigation, engine and fuel economy information.

The VW XL1 is beautifully engineered, incredibly efficient and as technologically advanced as any car in the market today. It is an unlikely "supercar" that might redefine how actual supercars will be like in the future. Too bad only 250 units of the XL1 will be made, and none of them is destined for our shores.

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This article first appeared in the November 2013 issue of Torque.


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