The Volkswagen XL1 is a coupe that 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.
Low-kg philosophy means low level of equipment, but everything’s easy to use and the build quality is very high.
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.
The visual field of the XL1’s so-called e-mirrors has been adjusted using a special computer programme.
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.
