We know that VW's futuristic hybrid eco-car packs phenomenal efficiency, but does the driving experience match up?

What is it?

A hyper-economical carbonfibre and gull-winged two-seater that is the culmination of more than a decade of engineering effort at Volkswagen. This started with Ferdinand Piech’s (now chairman of the VW supervisory board) turn-of-the-century vision of building a production car capable of covering 100km on one litre of fuel, or 282mpg.



The first concept was the 2002 L1, which combined a carbonfibre body, tandem seating, a side-hinged canopy and a single-cylinder, 8bhp, engine. The car weighed just 290kg. The L1 was demonstrated by Piech, who was then VW Group boss, and the company claimed fuel economy of 0.99-litres per 100km, or 238mpg.

The second-generation L1 was shown in Autumn 2009. This featured hybrid transmission combining a two-cylinder diesel engine and an electric motor. 

The problem with making the L1 production-ready was less the uncivilised tandem seating and aircraft-style side-hinged roof canopy and more the issue of it meeting crash test requirements.

Less than two years after the second-generation L1, VW showed the XL1 in the form of a series of driveable prototypes. VW engineers had taken a huge leap with the ‘one-litre’ concept by retaining the two-cylinder hybrid drivetrain but completely rethinking the body design. 


Bringing the story right up to date, the final design is based around a supercar-style carbonfibre reinforced plastic (CFRP) monocoque passenger cell, with the passenger seat staggered behind the driver seat. This clever arrangement reduces the amount of shoulder room needed, allowing the body to be as narrow as possible for aerodynamic reasons. Crash protection front and rear is provided by large extruded aluminium crash boxes and the mid-mounted powertrain is also hung off the rear aluminium subframe. The whole assembly weighs just 230kg.



To make for easier access across the wide sills, the XL1 has large gullwing doors which cut right into the roof. If you end up upside down in the XL1, explosive bolts release the gullwing doors.

The XL1 is 3.88m long, just 1.65m wide and 1.15m tall – which makes it 10cm shorter than a Volkswagen Polo, less than 20mm narrower but nearly 30cm lower.

These dimensions are, of course, at the maximum points. In the flesh, the XL1 looks tiny, not just because it so low, but also because the body tapers away to the classic teardrop shape with the rear wheels enclosed by the body. It has a Cd rating of just 0.189 - surely a world record for a production car.



The front suspension is made up of double wishbones, the rear a ‘semi-trailing link system’. The brake discs are made of lightweight ceramic and the wheels are magnesium. The front wheels are almost motorcycle-slim at 115/80 R15 and the rears 145/55 R 16.



Behind the passenger cell is the two-cylinder hybrid drivetrain. Effectively half of an existing 1.6-litre turbo diesel, tweaked and fitted with a balancer shaft, it develops 50bhp and the electric motor provides 27bhp. Both drive through a seven-speed DSG gearbox. The 5.5kWh lithium-Ion battery pack is mounted in the front of the car, in the void ahead of the passenger’s feet.

The XL1 can run on diesel only, electric only or, in boost mode, a combination of the two. During boost mode the two motors generate a maximum of 68.3bhp and a maximum of 103lb ft of torque. The XL1’s top speed is limited to 99.4mph and it can hit 62mph in 12.7secs.

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What's it like?

Exceptional on the motorway and agreeably flawed in town. It takes a bit of effort to get into the XL1, the sills are very wide and the seats very low, but once you’re inside, it is very comfortable indeed. The view ahead is panoramic, while the view directly behind is non-existent because there’s no rear window. The rear-view mirrors have been replaced by what looks like a pair of iPhone screens mounted in the door trims - the XL1 is the first production car in the world to have rear-view cameras in place of conventional mirrors.

 Top marks for the interior design, too. The dash is a model of restrained good taste and quality finish. There's a half decent boot, too. It's hidden in the tail and has room for a couple of large weekend bags.

Twist the key, put the shift lever into ‘D’ and the car hums away on battery power. Straight away you are aware of the different sensations that come from a car built around a carbonfibre monocoque. There’s a slight hollowness and resonance to the sounds transmitted into the cabin. As I accelerated and the – still cold – diesel engine fired up, the noise was alarming, a kind of empty reverberating thrum.



On a straight road the XL1 is very stable and straight-running, with easily enough power to keep up with traffic flow. It is surprisingly comfortable and quiet on decent roads. The steering is accurate and the swiftness and seamlessness of the engine cutting in and out is very impressive - even if it is relatively vocal. Even the smallest incline can be quickly detected by the XL1 and the engine almost instantly spun up to assist the electric motor and battery pack.



In town, the story is slightly less happy. The ride can be a little brittle and the unassisted steering takes some getting used to. It’s quite hard, say, to whip around a mini-roundabout because the steering weights up considerably. The brakes feel a little dead and are also a little noisy, but that’s a consequence of the lightweight ceramic brake discs.

And you have to move around in the seat to try to see properly at junctions: leaning forward to look around the A-pillars can lead to you banging your head on the low windscreen surround. Yes, it takes a little thought to drive around on narrow streets, but the learning curve is likely to be short.



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On the motorway, the XL1 is supreme. Despite its tiny footprint and the heavy rain on the Swiss motorway, the XL1 was rock-steady, completely unruffled by passing lorries. It ran very straight and true, requiring virtually no steering corrections. At a steady 62mph, the XL1 requires just 8bhp to make progress – an indication of the car’s remarkably low rolling and air resistance. It also feels entirely happy at 75mph and above, and making brisk overtaking manoeuvres.



On an early test drive this week, which including crossing a mountain range, the most economical drivers achieved a real 188mpg. On a long motorway run, there’s surely potential for 200mpg. Overall, the XL1 is quite an unusual experience, but a very satisfying one for any driver who appreciates the brilliant engineering behind the car.

Should I buy one?

Firstly, there’s no news about the price. VW bosses admitted at the Geneva motor show that they still have no idea how much the company will charge for the 250 production examples that will be made by Karmann. Whatever VW charges, there’s no doubt they’ll make a huge loss on the XL1 project, although that is hardly the point. It is a technological marvel.



And, while VW UK has requested as many as 50 of these left-hand-drive-only cars, there’s no news on how many will arrive here. 

All that said, the XL1 is a true landmark machine that points the way to the future – a future as far as a decade away. The combination of lightweight material, a downsized engine assisted by an electric motor, dramatically better aerodynamic performance and the innovations such as automatic coasting on downhill roads are definitely the future for family cars.



Super-early adopters will adore the XL1 – and the chance to hone their driving skills enough to achieve a real-world 200mpg. 



VW XL1

Price n/a; 0-62mph 12.7sec; Top speed 99.8mph; Economy 313mpg (claimed); CO2 21g/km; Kerbweight 795kg; Engine type in-line two, turbocharged, diesel 800cc and electric motor; Installation rear, transverse; Power 68.3bhp; Torque 103lb ft

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Marv 14 March 2013

Great potential

I think VW are to be applauded for pursuing this. As per the article, some the technology could filter down to other VAG products and provide vehicles offering ever increasing range, reduced emissions and reduce motoring costs for drivers. 

I'd love one for my pretty economical A1 TDi to cover my 150 mile round trip commute,  but alas fear the price would be prohibitive. 

steve49car 11 March 2013

Range?

No where is its range mentioned ... or how practical it might be ! Can I get golf clubs in the boot ... probably not so not much use then! As for the argument as to whether its petrol or diesel that is most likely to cause cancer .... no doubt you eat GMO foods and give it not a second thought ...never mind that its banned in France,Russia,India and others for good reason! Then of course there is mercury,flouride,aspartame (sweetener) ... the list goes on!

supertax 10 March 2013

A petrol engine would be

A petrol engine would be cheaper. Which is the point of economy. Also you could have a much smaller engine, half the size of the diesel one to give the same power, so making the XL1 even lighter.

And diesel kills tens of thousands of people a year in air pollution.

Diesel gets unfairly taxed cheaply.

In the UK and America a petrol version would make sense.