Volkswagen has lifted the veil on the definitive production version of its ultra frugal XL1 ahead of the distinctive new two-seater's public premiere at the Geneva motor show on March 5.
Click on photo for more views of the Volkswagen XL1.
Billed as the world's most fuel efficient road car, the teardrop-shaped coupe relies on a combination of exotic construction materials, a low kerb weight, compact plug-in diesel electric hybrid driveline and record breaking aerodynamics to deliver a spectacular combined cycle fuel consumption of 0.9 litres per 100km on the European test cycle – a figure, Volkswagen contends, provides the XL1 with a theoretical range of more than 500km on its tiny 10-litre fuel tank, while endowing it with average CO2 emissions of just 21g/km.
[Auckland to Wellington is around 630 km and diesel is currently selling at around NZ$1.50 a litre].
Capable of running on battery power alone, the new Volkswagen also possess a zero-emission range of up to 50km on its electric motor.
First displayed as a running prototype back in 2011, the carbon-fibre reinforced plastic bodied XL1 is set to enter limited production alongside the Volkswagen Golf cabriolet and Porsche Boxster at the former Karmann factory in Osnabruck, Germany next month.
At 3888mm in length and 1153mm in height, the XL1 is slightly shorter than the existing Volkswagen Polo but lower than the recently unveiled second-generation Porsche Cayman. Entry to the cabin is via butterfly style doors hinged within the windscreen pillar. Inside, the new Volkswagen provides accommodation for two, with the seats staggered slightly to free up shoulder room.
A series of extreme weight saving measures, including the use of specially developed carbon-fibre reinforced plastic just 1.2mm thick for the body, a windscreen with glass that is 3.2mm thick, a dashboard supported by a wood fibre material some 1.4mm thick and magnesium wheels, sees the XL1 hit the scales at just 795kg in production trim.
In a formal presentation for the new car in Osnabruck, Volkswagen's head of research and development, Ulrich Hackenberg, revealed the German car maker had developed a new nine-stage production process for its most fuel efficient model based around a weight saving injection moulding process, which he says will heavily influence other future production models.
“The XL1 is a car of the future that is being built today. Only 23 per cent of it is constructed from conventional steel. The rest is distributed among various polymers, alloys, natural fibres, process materials and electronics,” he told Drive.
The diesel-electric hybrid drivetrain, which is also planned to be fitted to Volkswagen's entry level Up city car to create a more affordable fuel miser, is mounted at the rear of the XL1's cabin. Weighing just 227kg in all, it is based around a turbocharged 800cc two-cylinder common rail diesel powerplant that is mounted transversely and develops 35kW and 120Nm.
The efforts of the combustion engine are supported by a brushless electric motor mounted in the forward section of the new car's seven-speed dual clutch gearbox, where it delivers 20kW and 140Nm. Energy for the electric motor is provided by a 5.5kWh lithium-ion battery sited up front in the nose. It can be charged both via regular mains power or recuperated energy produced primarily under braking.
Together, the diesel engine and electric motor provide the hi-tech Volkswagen with a combined system output of 51kW and 140Nm, with drive delivered to the rear wheels.
The driver can choose between two modes: diesel-electric or pure electric. In the latter a clutch within the gearbox disengages the diesel engine. It is then brought back into the drive process by what Volkswagen describes as "pulse starting", in which the electric motor's rotor is sped up and coupled to the clutch. This accelerates the internals of the diesel engine to the required speed and starts it.
Volkswagen claims 0-100 kmh acceleration in 12.7sec on the way to a top speed limited to 160 kmh. However, the German car maker is downplaying the XL1's straight line performance, preferring instead to focus on its fuel saving qualities. As a measure of its overall efficiency, Volkswagen claims the new coupe requires just 6kW to cruise at a constant speed of 100 kmh, resulting in the combined cycle consumption headline figure of 0.9L/100km.
Helping the XL1 achieve such outstanding fuel efficiency is its slippery shape. Extensive wind tunnel testing has netted the new car a drag co-efficient that easily beats any existing series production road car at 0.189. Further wind cheating measures include the adoption narrow 15-inch front and 16-inch rear wheels shod with specially developed low rolling resistance Michelin tyres with a unusual profile of just 115/80 at the front and more conventional 145/55 at the rear.
Underpinning the new two seater is a unique platform structure supported by a chassis featuring a aluminium double wishbone front and semi-trailing arm suspension at the rear. Weight saving efforts extend to the anti-rolls bars and brake discs, which are made of carbon-fibre reinforced plastic and carbon ceramic materials respectively.
The XL1 will initially be produced in a run of just 50 cars. After that, Volkswagen says production will be altered to meet demand. Pricing has yet to be announced.
-Fairfax News Australia
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