The XL1 car was designed to be able to travel 100 km on 1 litre of diesel (280 mpg‑imp; 240 mpg‑US), with a fully charged battery, while being both roadworthy and practical.

For light weight, the car uses an unpainted carbon fibre skin over a magnesium-alloy subframe.

Individual components have been designed to be low weight, including engine, transmission, suspension, wheels (carbon fibre), brakes (aluminium), hubs (titanium), bearings (ceramic), interior, and so on.

The gear selection (forwards, reverse or neutral) is made using a switch on the right-hand side of the cockpit.

The engine is switched off automatically during deceleration and stops, and auto-restarted when the acceleration pedal is pressed.

At the 2007 Frankfurt Motor Show senior VW exec Ferdinand Piëch claimed the car would be available by the end of the decade.

[10][11] Around June 2008 car magazines were reporting a powerplant change to a two-cylinder diesel-electric hybrid.

[10][11] The second Volkswagen 1-litre car, named L1, was first shown to the public at the 2009 Frankfurt Motor Show.

The 800 cm3, twin-cylinder, common-rail turbodiesel is joined by a 10 kW (13.4 hp) electric motor and has a CO2 emission 39 g/km.

Displacing 800 cm3 (49 cu in), it is rated at 35 kW (47 hp) and 121 N⋅m (89 lb⋅ft) of torque and transmits power to the rear wheels through a seven-speed DSG transmission.

The electric motor pitches in with 20 kW (27 hp) and 100 N⋅m (74 lb⋅ft) of torque, and can work in parallel with the diesel or drive the car independent of it.

However, the car is much lower with a height of only 1,184 mm (46.6 in), and has a coupe-like roofline, reducing interior volume.

[20] The production version of the plug-in diesel-electric hybrid was unveiled at the 2013 Geneva Motor Show.

[5] One reviewer found that, in real-life traffic, with air conditioning on and without attempts at hypermiling, the car is able to reliably achieve 2.3 L/100 km (100 mpg‑US; 120 mpg‑imp).

Because more than 200 potential buyers registered, a drawing was conducted to select the customers with a purchase option for the available cars.