Volkswagen XL1 is a plug-in hybrid two-seater prototype presented at the Qatar Motor Show 2011 which equipped with electric motor and combustion engine offers fuel consumption of just 0.9 l/100 km. In this way, it becomes more fuel-efficient hybrid in the world, approaching a more mass production at a similar time.A successful experience that will soon be a reality
The XL1 Volkswagen is the third prototype that develops brand strategy under the car of 1 liter per 100 km average consumption that began years ago, the Chairman of the Supervisory Board of Volkswagen Group, Ferdinand Piech.
New housing built with high-tech materials
XL1 Volkswagen chassis is manufactured using advanced technology and modern materials. It measures 3,888 mm long, 1,665 mm wide and 1,156 mm high, with the first two dimensions similar to the Volkswagen Polo and the height close to that of the Lamborghini Gallardo Spyder. The wheelbase is 2,224 mm.
Suspensions schemes have a double axle wishbone front and rear axle swing arms bent back, but very compact designed to provide a comfortable on-road dynamism. Moreover, both trains have been fitted roll bars, which are complemented by two electronic aids: ESP electronic stability control and ABS anti-lock system. The tires are low friction, new generation, developed by Michelin, measuring 115/80R15 front and 145/55R16 rear.
Lightweight construction and safer with CFRP
The new XL1 is not only a vehicle especially light, but also very safe thanks to its new body, monocoque type similar to that of Formula 1 cars, built in reinforced plastic CFRP carbon fiber. The difference with the cars of high competition is that the occupant cell XL1 is closed for security reasons so depending on the type of collision, and B-pillars, roof rails and footrests can act load as pillars of absorbing the impact energy. Additional cross rails and located in the front and back of XL1 further optimize passive safety.
The body of the XL1, including the monocoque with front seats, slightly displaced and attached external parts have been manufactured, too, reinforced plastics, CFRP carbon fiber.
XL1 Volkswagen parts are made of carbon fiber sheets, arranged along the lines of force flow and molded by an epoxy resin system applied by the method ARTM (Advanced Resin Transfer Moulding / resin transfer molding advanced .) This mixture of materials is a composite material extremely strong and light, giving a total weight of just 795 kilograms, broken, 227 kg corresponding to the complete propulsion unit, 153 kg of the chassis, electronics 105 kilograms and 80 kilograms of equipment .
Adding these amounts, there are still 230 kg under the weight of the monocoque body, including doors and the windshield made of extremely fine crystal. Other materials used in the Volkswagen XL1, in addition to CFRP and aluminum, the ceramic disc brakes, magnesium wheels and plastic wheel structure.
Furthermore, the concept of body design is extremely innovative. Compared to the Volkswagen Golf, it has a drag coefficient of 0.693 m2 resulting from the multiplication of Cw (0.312) x A (frontal area 2.22 m2).
Given that this is a compact, the result is excellent, so we can say that the Volkswagen Golf is a car significantly streamlined. At the same time, the Volkswagen XL1 reduces this value by offering a drag coefficient of 0.277 m2, resulting from the multiplication of Cw (0.186) x A (frontal area 1.50 m2), so that the XL1 is 2.5 times more streamlined the Volkswagen Golf.
A new era in the approach to design DNA
The body design of the Volkswagen XL1 is based on drawing lines of the model presented in 2009, adapting without concessions to the laws of aerodynamics. The front of the prototype is wider than the rest of the car which narrows as we move towards the rear.
The front is characterized by the typical horizontal lines of the new Volkswagen design DNA and a continuous transverse black band, located at the usual place on the grid, which integrates efficient LED headlights. Under these, the lights are intermittent in the form of two narrow vertical LED strips that fit perfectly to the shape of the wheel arches. In the bottom of the front section, a power-operated blades are activated when necessary to cool the diesel twin engine, battery and air supply to the indoor climate system.
The silhouette of the roof is based on a path of lines that form a large arc from the front pillar to the rear. While the front wheels are exposed, the rear has been fully faired to reduce turbulence. Both front and rear wheels, some spoilers have been implemented to optimize the deflection of air. In addition, as a prototype for excellent efficiency, has no side mirrors, items that have been replaced by small cameras in the swinging doors that carry the catch to two screens in the interior.
They draw attention to the double doors, similar to sports models, which have been attached to two points on the body, below the front pillars and roof rack, just above the windshield, using aluminum joints. When activating the opening mechanism, the doors not only can be folded up, but can slide slightly forward, so there is a generous and ample access and lowering the car.
At the rear, the design reinterprets the brand parameters: precision and quality, but lacks rear window under which integrates a large tailgate which in turn holds the propulsion unit and the large trunk of 100 liters. A band of LED, red, runs along the upper and back sides of the framing, integrating the functions of lights, reverse lights, fog lights and brake lights. In the lower section of the rear bumper, black diffuser extends almost continuously, completely covered to low.
Interior for two occupants
Unlike the two previous prototypes presented in 2002 and 2009, as an interior two-seater was also available but in tandem aerodynamic issues in XL1 Volkswagen has changed these settings offering two parallel seats, identical to the model as Volkswagen Polo or Golf.
The most modern technology and advanced efficiency of the moment
The prototype of the Volkswagen XL1 is an example of clean and efficient technologies saving without being at odds with the driving pleasure. Rear wheel drive, the German manufacturer has opted for a hybrid system with diesel engine and a Plug-in battery charge.
For the thermal combustion engine, Volkswagen has developed a new two-cylinder engine with 800 cubic centimeters, derived from the 1.6 TDI CR block, containing the same technology as this, with the power system common rail direct injection and the same dimensions ( bore and stroke) of the cylinders and also with the same special piston cavities, multiple injection and individual orientation of each jet injection, delivering a maximum output of 48 hp.
Additionally, the shaft driven off the crankshaft rotates at the same speed, optimizing the engine running smoothly. The aluminum box of the new twin engine crankshaft TDI has been specially designed so that friction losses are as low as possible and also has a system of exhaust gas recirculation EGR, oxidation catalytic converter and particulate filter diesel, elements that allow compliance with Euro 6 emissions standard.
The cooling system provides a highly efficient design means the engine management only activates the electric water pump to cool the diesel engine when the engine operating conditions so require. The second electric water pump, which is only activated if necessary, is responsible for cooling the starter generator and power electronics using individual water cycle at low temperatures.
If maximum power is required, the electric motor develops a torque of 100 Nm from idle, can act as a booster to strengthen the TDI engine which in turn offers a couple of 120 Nm. When the electric motor and the TDI function simultaneously in booster mode, develops a maximum torque of 140 Nm.
The performance of the prototype Volkswagen XL 1 surprise themselves, with acceleration from 0 to 100 km / h in just 11.9 seconds and reaching a top speed governed to 160 km / h. The power consumption is only 0.9 l/100 km and CO2 emissions of 24 g / km, giving a maximum range of 550 miles on a tank of 10 liters of fuel and set mode.
Mode plug-in hybrid plug-in
XL1 equipped prototype plug-in hybrid system (plug-in) based on a direct injection turbo diesel common rail TDI and automatic dual-clutch seven-speed DSG.
The full hybrid drive is located at the rear of the car, while the hybrid module has been integrated within the transmission housing between the TDI engine and the 7-speed DSG gearbox.
The hybrid drive consists of an electric motor delivers maximum power of 27 hp and clutch. The electric motor is powered by a lithium ion battery, controlled by power electronics, with a voltage range of 220 volts, which manages the flow of high voltage energy to and from the battery or the electric motor respectively. XL1 electrical system receives the necessary 12-volt power through a DC / DC converter.
Operation of the TDI diesel engine and electric motor
The electric motor serves to support the TDI during acceleration, so Booster. But it is also capable of propelling, by itself, the prototype Volkswagen XL1 at distances up to 35 kilometers. In this case, the TDI diesel engine is disengaged and disconnected from the clutch drive train sandwiched opening. Meanwhile, the clutch located near the gear box is closed, which means that the DSG is fully integrated.
By pressing a button on the dashboard, you can connect the electric mode, so CO2 emissions are zero. When the battery is discharged or demand an extra dose of power, then activated the diesel combustion engine increasing the power of electric motor rotor and quickly closing the clutch located near the engine, accelerating to reach the required speed and then starts . This process is done quickly and quietly.
As soon as the prototype braking, the electric motor acts as a powerful generator that uses the energy from braking to recharge the battery. Under certain operating conditions, a displacement of electric charge point favoring the TDI hybrid system's energy balance and consequently the consumption of turbo which now runs more efficiently.
The gear selection in the DSG is always to reduce to a minimum, fuel and power, managed primarily by the power electronics required according to demand. In order to select at each moment the type of propulsion in each situation is necessary to evaluate parameters such as throttle position E-Gas engine load, energy reserves and the mixture of the kinetic and electric.



