VW L1 Concept Officially Revealed in Detail

VW L1 Concept 2009 - 1600
VW L1 Concept 2009 - 1600

Volkswagen's 1-litre car the L1 Concept has been updated for the 2009 Frankfurt Motor Show. New pictures presented to the German media over the weekend show a different-looking car. Originally unveiled back in 2002 the idea was to use all the technical possibilities the company had to build a car that could conceivably use no more than one litre of fuel per 100km traveled. Such a thing has never been done before with fossil fuel-powered cars.

The update apparently uses a two-cylinder diesel engine worth 22kW (29hp) and mated to the new 7-speed DSG transmission. The car apparently weighs about 380kg (838 lbs) and can achieve an unbelievable 1.2 litres per 100km (189.6mpg) on average.

Apart from the engine other ways utilised to make these figures happen include using extremely light but exotic materials like the plastic bodywork, the monoblock engine construction and the titanium exhaust system. The fuel pump housing of the original was made of magnesium.

The L1 is not particularly large as it measures around 1.25 metres in width, enough for the two passengers to sit in tandem. The new concept also picks up on VW's latest styling cues like the slimmer front grille and it has covered rear wheels.

Wait for it to be officially unveiled in less than a day.

[UPDATE] Detailed press release and 3 new hi-res photos added to article.


World Premiere of the L1


The Future Needs the TDI:

  • Small TDI leverages minimal fuel consumption and maximum range
  • Downsizing - 0.8 TDI is smallest diesel engine intended for production applications ever built by Volkswagen
  • Electrifying idea - E-motor plus TDI pushes CO2 emissions down to 36 g/km

The TDI, E-motor and 7-speed DSG are located at the rear, and they combine to create the most fuel efficient road-legal car hybrid drive in the world. Proof of this are its 1.38 litre per 100 kilometres fuel consumption and 36 g/km CO2 emissions. Serving as the primary drive source is a completely redeveloped two-cylinder turbo-diesel with common rail direct injection (TDI). It is operated in two different modes depending on the load conditions. In the standard "ECO" mode, the 800 cm3 TDI develops a power of 20 kW / 27 PS (at 4,000 rpm); in "Sport" mode - used to reach top speed, for example - the car's power rises to 29 kW / 39 PS (at 4,000 rpm). The TDI's maximum torque is 100 Newton-meter (at 1,900 rpm). Naturally, the L1 also has a Stop-Start system that automatically shuts down the engine when vehicle has stopped and restarts when the accelerator or E-pedal is pressed.

The hybrid module has been integrated into the housing of the 7-speed DSG (Direct Shift Gearbox). It is located between the TDI engine and the DSG gearbox and consists of a 10 kW / 14 PS electric motor and a clutch. The E-motor is supplied with energy from a lithium-ion battery located at the front of the car. An electronic power control module, operating at around. 130 Volts manages the flow of high voltage energy the battery and to the E-motor. In parallel, the vehicle's low voltage electrical system is supplied with the necessary 12 Volts through a DC/DC converter.

Electric motor - details of the E-motor

In normal operation the electric motor can support the TDI engine in conditions such as by electronic load point shifting and in acceleration. If necessary - generally during acceleration - the E-motor can supply 40 percent additional torque over the entire speed engine speed range. Moreover, the E-motor can propel the L1 over short distances by itself. In this case, an auxiliary clutch decouples the TDI from the drivetrain. Restarting the TDI is a very easy process. In so-called "pulse starting" of the TDI, the electric motor is sped up and is then coupled to the TDI unit to provide almost instant starting. The entire process takes place automatically and without jolts, so the driver hardly notices the restarting of the TDI engine.

In braking phases, the E-motor operates as a generator to charge the lithium-ion battery by recovering braking energy. The gears of the automatically shifting DSG are always selected with the aim of achieving the best possible fuel economy. The engine controller regulates all energy flow and drive management tasks taking into account the moment by moment demands for power made by the driver. Some of the parameters used to calculate the optimum propulsion mode for the given conditions are: accelerator pedal position, engine load, momentary fuel demand, energy supply and the mix of kinetic and electrical energy at any given time.

Diesel engine - details of the 0.8 TDI

The TDI engine in the L1 is a new development. Yet, even here Volkswagen has been able to exploit synergies to design an engine that is both innovative and cost-effective. Hence, this 0.8 litre TDI unit has been derived from the 1.6 TDI just introduced a few months ago. The 1.6 TDI is making its debut at the IAA in cars such as the new version of the Golf BlueMotion (3.8 l/100 km) and the Passat BlueMotion (4.4 l/100 km) - which are currently the world's most fuel-efficient production cars in their respective classes.

Based on their common origins, the 0.8 TDI and 1.6 TDI have identical cylinder spacing (88 millimetres), bore (79.5 millimetres) and stroke (80.5 millimetres). These high-tech TDI engines also share key internal engine features for reducing emissions. They include special piston crowns, multi-injection and individual orientations of the specific injection jets. On both drivetrains there is exhaust gas recirculation, an oxidation catalytic converter and a diesel particulate filter. Equipped this way, the TDIs in each Volkswagen fulfil the limits of the Euro-5 emissions standard with ease.

The 1.6 TDI, thanks to its common rail injection, is also an exceptionally quiet and low-vibration diesel engine. These positive properties have been successfully transferred to the two-cylinder unit. The TDI's aluminium crankcase was also constructed with high precision to achieve very low friction losses. The oil pump, designed to operate at a maximum oil pressure of 4.0 bar, also contributes to engine efficiency.

Another example of how the entire drive system is configured for high efficiency is the L1's cooling system. Its external water pump is controlled by engine management so that cooling is only activated while engine operating conditions require it. This thermal management also contributes to reduced fuel consumption. A second electric water pump, also activated only when needed, provides cooling required for the starter generator and the power electronics in a separate water circulation loop operating at a lower temperature level.

Automatic transmission - details of the 7-speed DSG

Gear shifting work aboard the L1 is handled by the 7-speed DSG, which is one of the most innovative automatic transmissions in production. Compared to the version equipping the new Polo, for example, the design of the Direct Shift Gearbox has been developed to include clutch control for the hybrid module. Furthermore, individual gear ratios have been optimised to attain responsive driving performance despite the car's extremely low fuel consumption. The hybrid module is integrated into the DSG housing as previously mentioned. It is located where the flywheel is usually to be found.

Driving performance - economical and yet responsive

The L1, equipped with ABS and ESP, has a top speed of up to 160 km/h - this is remarkable considering its fuel efficiency. With maximum acceleration from a standstill, the two-seater reaches 100 km/h after just 14.3 seconds. The fuel tank holds just ten litres yet, this is sufficient for a theoretical driving range of about 670 kilometres, given the car's 1.38 litre average fuel consumption.


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Comments (11)

kimbo kimbo
old idea with worse mileage than the orginal concept. Is VW going backwards or what?
Sep 16th, 2009 6:28am
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Santo Santo
Come on kimbo, this version has ABS, Airbags and full equipment, I thing they do it very well =)
Oct 1st, 2009 7:46pm
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eddie eddie
Great concept. It is wonderful how all this neat stuff is coming out. Technology rules!
Sep 15th, 2009 11:53am
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eddie eddie
Sep 15th, 2009 11:52am
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DieselDog DieselDog
NICE! Makes more sense to me than a motocycle or a scooter (as it gets better mileage and can be used in foul weather. This would make an ideal long-distance commuter car. I'll take one!
Sep 15th, 2009 7:44am
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genie genie
I use my motorcycle in foul weather all the time, and though this does get better mileage, my bike (like most bikes) has a 0 - 62 time of less than 5 seconds, uses 4L/100km combined, plus its narrow enough to weave through heavy city traffic. Which in my mind makes it much more practical than this coffin. Still, if the tech can trickle down from this to other cars, then that can only be a good thing.
Sep 15th, 2009 11:56am
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nederina nederina
i like it. nice one vw! but how bout putting the vw up! for production?
Sep 15th, 2009 5:46am
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Dlaor Dlaor
Sep 15th, 2009 5:22am
0 0
Looks better than the 2002 version. But what does this thing with a 7 speed? Must be terrible to change gear every 15 miles or so. The 2002 version had a topspeed 75 mph, I'm suprised if this goes faster than 115 mph with the extra 20 hp.
Sep 15th, 2009 3:29am
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Oliver Oliver
Nice car + 190 mpg= Great job VW!
Sep 14th, 2009 11:20pm
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Renegade Renegade
Ewww...this is so damn ugly and strange looking.
Sep 14th, 2009 10:24pm
0 0