A decade ago, well before the electric vehicle revolution now engulfing the planet, Volkswagen came out with a quite amazing, and incredibly fuel-efficient production
car – the XL1.
The company had been working on the development of an epically efficient car for quite a while, and its catalogue of work in the area included vehicles such as the 1L and L1 cars in the preceding years. The names of those vehicles are a giveaway as to the thinking and technology behind their efficiency, with both fashioned on the idea of pairing super-sleek aerodynamics and a hybrid power system to create a vehicle capable of covering 100km on one litre of fuel. This work would culminate in the XL1, the production version of which was revealed at the Geneva Motor Show in 2013.
So how efficient was the XL1?
The small, slippery machine was powered by a plug-in hybrid system consisting of a 35kW/120Nm, 800cc two-cylinder TDI diesel engine; a 20kW/140Nm electric motor, a 5.5kWh battery and a 7-speed DGS gearbox. The compact powertrain was mounted behind the cabin and drove the rear wheels. Construction was very lightweight. The chassis and body were made of carbon fibre, running gear weight was reduced by the use of aluminium parts (including suspension components, brake callipers, dampers, steering gear housing), CFRP (anti-roll bars), ceramics (brake discs) magnesium (wheels) and plastics (steering wheel body).
The whole car weighed in at just 795kg and along with incredibly low drag co-efficient of 0.189, the XL1 could claim a combined fuel consumption of 0.9 litres per 100km. Phenomenal.
The battery could be charged from a conventional household electric outlet and battery regeneration was employed to recover energy.
The electric motor supported the diesel engine in acceleration but could also power the XL1 on its own for a distance of up to 50km. In this mode, the TDI decoupled from the drivetrain by disengaging a clutch and was shut down. Meanwhile, the clutch on the gearbox side remained closed, so the DSG fully engaged with the electric motor.
While the XL1 looked like it could break speed records – and had some decidedly supercar-like features such as the wing doors – that wasn’t quite true. With the full power of the hybrid system engaged, it could reach 100 km/h in 12.7 seconds and reach an electronically limited top speed of 160km/h.
The XL1 went into production in 2013, with VW building 250 units. At the time, the company said that ‘the new XL1 shows the way forward for extreme economy vehicles and clean technologies.’ Back then, of course, there were but a handful of battery-electric vehicles – amongst them were the Mitsubishi i-MiEV (2009), the Nissan Leaf (2010) and the Tesla Model S (2012) for example – and, perhaps, there was a chance that the XL1 tech might have caught on. However, 10 years on and VW, and just about everyone else, has gone all-in on battery-electric tech. Things move fast in the automotive world.
Source: Motor Trader e-Magazine (August 2023)
20 August 2023