At the 2009 Frankfurt Motor Show Volkswagen has presented the L1 Concept, a diesel-electric hybrid vehicle constructed from aluminium and carbon fibre weighing just 380 kg and capable of returning 189 mpg (80.3 km/l) on the combined cycle while emitting just 39 g/km of CO2.
The L1 can seat two occupants in tandem. They enter through a side-hinging, electrically operated canopy to maximise the aerodynamic efficiency of the L1 Concept. The result is a remarkable coefficient of drag figure of just 0.195.
The safety cell, constructed from carbon fibre reinforced plastic, weighs just 124 kg.
Every element of the L1 Concept is intended to maximise efficiency.
At its heart is a tiny 800 cc two-cylinder common rail, direct injection TDI engine. In ‘ECO’ mode the engine develops 27 PS at 4,000 rpm, in ‘Sport’ mode this rises to 29 PS and 74 lbs ft of torque developed at 1,900 rpm.
At 3,813 mm in length, the L1 Concept is comparable to the Fox yet at just 1,143 mm in height it’s as low as a Lamborghini Murcielago. Its width, at just 1,200 mm, is narrower than any conventional car on sale today.
The adjustable front seat is thin and constructed from carbon while the rear passenger sits in a fixed seat built into the monocoque.
The driver has an excellent view of the road and sits behind an instrument panel set into the body of the car.
The rear view mirror is replaced by an organic light-emitting diode display while the main controls for the operation of the vehicle are grouped around the steering wheel.
The modest kerb weight of the L1 Concept linked to efficient aerodynamics mean that it is capable of accelerating to 62 mph from rest in 14.3 seconds before reaching a top speed of 99 mph.
The 800 cc engine is derived from the 1.6-litre TDI engine found in the new Golf BlueMotion, also making its debut at the Frankfurt Show. The two have identical cylinder spacing, bore and stroke as well as exhaust gas recirculation and diesel particulate filters to ensure they meet and exceed the Euro-5 emissions regulations.
Under normal conditions the 14 PS electric motor is inactive, only engaging when additional acceleration is required, delivering 40 per cent extra torque. In addition, the electric motor can take over from the engine to power the L1 Concept for short distances.
The L1 Concept draws inspiration from the original 1-litre car, unveiled in April 2002 when Dr. Ferdinand Piëch, then Chairman of the Board of Management, drove the concept between Wolfsburg and Hamburg.
“It is an enormous challenge to control costs in producing the monocoque out of CFRP,” says Dr. Ulrich Hackenberg, member of the Board of Management for the Volkswagen Brand with responsibility for development.
Both technically and visually, the CFRP body is already considered a significant achievement in car design. Unique on this car are the proportions of its dimensions.
"While the length of the L1 at 3,813 millimetres is still similar to that of a Volkswagen Fox, and its height of 1,143 millimetres nearly matches that of a Lamborghini Murciélago, the car’s aerodynamically optimised width (1,200 millimetres) has no comparisons in the world of today’s production cars.
"The key starting point was body construction, and a core question was raised here: How would a car have to look and be built to consume as little energy as possible?
The logical answer: extremely aerodynamic and lightweight. Yet these objectives had to be achieved under a non- negotiable precondition: a maximum of safety. The approach taken: a narrow two-seater with a CFRP body.
"The seat layout fitting this design goal was dictated by the uncompromising aerodynamic form of a glider: One seat behind the other.
"Entry to the concept car is also similar to that of a glider; through a roof cover hinged at the side. On this second generation of the L1, the concept has been further honed; each component has been redesigned, a special chassis with aluminium components was developed, and above all the crucial CFRP technology from Formula-1 racing and airplane construction was transferred to automotive manufacturing. "