Volkswagen XL1 (2014–2016)
The Volkswagen XL1 Super Efficient Vehicle (SEV) was unveiled at the Qatar Motor Show. Pioneering construction techniques, an advanced plug-in hybrid drivetrain and innovative packaging all play a part in allowing the XL1 to return 313 mpg on the combined cycle while emitting 24 g/km of CO2 to set a new benchmark for vehicle efficiency.
Powering the XL1 is a compact 800 cc TDI two-cylinder common rail diesel engine developing 48 PS. It’s linked to an electric motor producing 27 PS, resulting in a total of 75 PS – a modest output yet more than enough when the low kerb weight (795 kg) of the vehicle is taken into account.
The TDI engine is linked to an electric motor and a seven-speed DSG gearbox with an automatic clutch mounted between each unit. The electric motor can either work independently of the TDI engine or in tandem when accelerating. In pure electric mode the XL1 can travel up to 35 km before the diesel engine cuts in. Accelerating from rest to 62 mph can be achieved in 11.9 seconds; the electronically limited top speed is 99 mph.
In both its styling and packaging the XL1 draws on lessons learned from the 1-Litre car (2002) and the L1 concept (2009). The XL1 has evolved to feature staggered seating with the driver and passenger placed next to each other in a body structure made from advanced new materials providing immense strength yet weighing just 230 kg.
To make such weight savings possible, and yet viable for series production, Volkswagen developed and patented a new system for the manufacture of the Carbon Fibre Reinforced Polymer (CFRP) parts on the car called the Resin Transfer Moulding (RTM) process.
In total the XL1 weighs 795 kg. In addition to the body structure, the weight is accounted for by the drivetrain (227 kg), the running gear (153 kg), the interior including a pair of bucket seats (80 kg) and the electrical system (105 kg). In total just 23.2 per cent of the car (184 kg) is made out of either steel or iron.
Further savings are made through the extensive use of lightweight materials including magnesium (wheels), ceramics (brake discs) and aluminium (dampers, steering system, brake calipers).
The styling of the XL1 is borne out of functional requirements – easy access to the interior is granted via a pair of elegant scissor doors that hinge on the A-pillar while the profile of the car has been honed in the wind tunnel, the result being a remarkable coefficient of drag figure of 0.186. The XL1’s overall length (3,970 mm) and width (1,682 mm) are similar to those of a Volkswagen Polo yet its height (1,184 mm) is more akin to that of a Lamborghini Gallardo Spyder.
Although the XL1 is still very much a concept, its unveiling marks the next step towards the birth of a new class of Super Efficient Vehicles, while the advent of a process such as RTM is a significant milestone.
Evolution of Volkswagen’s Super Efficient Vehicle class
|XL1 (2011)||L1 (2009)||1-Litre (2002)|
|Construction method||CFRP monocoque and add-on parts||Aluminium and CFRP||Magnesium and carbon fibre|
|Internal combustion engine||TDI, two-cylinder
35 kW / 48 PS, 120 Nm
39 PS, 100 Nm
8.5 PS, 18.4 Nm
|Electric motor||20 kW / 27 PS, 100 Nm||10 kW / 14 PS||n/a|
|Gearbox||7-speed DSG||7-speed DSG||6-speed automated|
|Emissions class||Euro 6||Euro 6||n/a|
|Kerb weight||795 kg||380 kg||290 kg|
|Performance / fuel economy|
|Top speed, km/h||160 (electronically
|160 (electronically limited)||n/a|
|0-100 km/h, secs||11.9||14.3||n/a|
l/100 km / mpg
|0.9 / 313||1.38 / 189||0.99 / 285|
|CO 2 emissions, g/km
|Range: E-drive||35 km||n/a||n/a|
|Range: TDI + E-drive||approx. 550 km
(10 litre fuel tank)
(10 litre fuel tank)
(6.5 litre fuel tank)
Volkswagen confirmed that its XL1 Super Efficient Vehicle, the most fuel-efficient production car in the world, with a fuel consumption value of 0.9 l/100 km (approx. 313 mpg) will go into production at the company’s Osnabrueck factory in Germany. Thanks to its plug-in hybrid system, the two-seater can also cover a distance of up to 50 km in all-electric mode and therefore with zero local emissions.
UK pricing of XL1 announced at £98,515
(RRP OTR) A total production run of around 200 XL1 models are being built at Volkswagen’s Osnabrück factory in Germany, a proportion of which will be made available for the UK.
The design brief for the XL1 was to produce a ‘one litre’ car – that is to say, a car that uses one litre of fuel per 62mph, equivalent to 282 miles per gallon. The resulting vehicle uses just 0.9 litres per 100 km, or 313 mpg on the official combined cycle, and this high mpg figure correlates to a very low carbon dioxide emissions value of just 21g/km. This is achieved using a two-cylinder 48PS 800cc diesel engine with a 27PS electric motor, driving through a modified seven-speed DSG transmission.
The XL1 was also aerodynamically optimised, adopting the classic ‘tear drop’ shape and utilising innovations such as removing traditional wing mirrors and replacing them with small cameras called e-Mirrors which transmit exterior images to interior displays. With a drag coefficient of 0.189 the XL1 can maintain 62mph on a level road in still air using just 8.4PS.