The Audi A8 hybrid combines the performance of a six-cylinder with the fuel economy of a four-cylinder model. With 180 kW (245 hp) of system power, the 2.0 TFSI and the electric motor deliver powerful thrust, yet the brand's flagship consumes just 6.3 liters of fuel per 100 km (37.34 US mpg). The ultra lightweight aluminum body plays a major role in this efficiency.
The Audi A8 hybrid is a parallel hybrid - a high-efficiency concept. Its 155 kW (211 hp) 2.0 TFSI and the electric motor are mounted one directly behind the other and are linked by a clutch to work together, when necessary. System output is 180 kW (245 hp) and peak system torque is 480 Nm (354.03 lb-ft). The power is delivered to the front wheels via a highly modified eight-speed tiptronic. The lithium-ion battery in the rear provides 1.3 kWh of energy, and its sophisticated air cooling system switches between two stages as needed.
The Audi A8 hybrid combines the performance of a six-cylinder with the fuel economy of a four-cylinder model. The sprint from 0 to 100 km/h (62.14 mph) takes just 7.7 seconds, and top speed is 235 km/h (146.02 mph). In the standard cycle, the large sedan consumes just 6.3 liters of fuel per 100 km (37.34 US mpg) on average - a CO2 equivalent of 147 grams per km (236.57 g/mile), and easily the best in its class.
Timeless and distinctive: the design
The exterior design of the large sedan is one of timeless elegance. The standard LED headlights give the front end an unmistakable expression. The Audi A8 hybrid is 5.14 meters (16.86 ft) long; the long-wheelbase Audi A8 L hybrid is 13 centimeters (5.12 in) longer.
The interior features sporty and lightweight lines, simple controls and a finish of handcrafted quality. The driver can read all key information about the hybrid drive on special displays. The seats are available with optional ventilation and massage functions, while the ambient lighting package uses LEDs to set subtle accents. Other features include a continuous center console and a folding table.
Audi offers a wide range of infotainment systems for the A8 hybrid. The Bose surround sound system is standard, with a high-end system from Bang & Olufsen available as an option. The optional navigation and infotainment system MMI navigation with MMI touch includes a touchpad for entering letters and numbers.
The ideal complement to this media center is the online Bluetooth car phone, which connects to the Internet via UMTS. Passengers can use its integrated WLAN hotspot to surf and e-mail. For the driver, the system delivers the services of Audi connect to the vehicle, including up-to-the-minute Audi traffic information online.
The assistance and safety systems that Audi offers in the A8 hybrid are also state of the art. These include the night vision assistant with highlighting of detected pedestrians and a parking system that supports the driver with four small cameras. The safety system Audi pre sense basic is also standard.
The Audi A8 hybrid will launch in Europe in May 2012. The standard-wheelbase version has a base price of €77,700, while the long version lists for €85,400.
Quiet on board: Active Noise Control
The Audi A8 hybrid comes standard with Active Noise Control (ANC). This innovative system eliminates intrusive engine noise by broadcasting a precise antiphase sound to the cabin through the sound system's speakers. This principle is known as interference: If two waves of the same frequency are superimposed, their amplitudes cancel each other out provided that they are equal and 180 degrees out of phase from one another.
A highly modified eight-speed tiptronic transfers the power to the front wheels. Instead of a torque converter, it includes the disk-shaped electric motor, which is combined with a multi-plate clutch operating in an oil bath. The clutch connects and disconnects the electric motor and the TFSI very precisely and gently.
With its eight widely spaced gears, the comfortably and fast-shifting hybrid transmission contributes significantly to the efficiency of the Audi A8 hybrid. When the 2.0 TFSI is deactivated, an electric pump maintains the oil pressure in the hydraulic system to safeguard the convenient start-stop feature.
The power electronics, connected to the battery and the electric motor by high-voltage cabling, are located in the plenum chamber of the engine compartment. They serve as a controller between the battery, which outputs direct current, and the electric motor, which operates on alternating current. Innovative technologies keep the volume and weight of the component low, with cooling provided by a separate water-filled circuit. The power electronics include a DC/DC converter that connects the consumers in the 12 V electrical system to the high-voltage network.
Electric drive is a permanent magnet synchronous machine; it serves as an electric motor, as a starter and - during deceleration - as a generator. The electric motor, which delivers up to 40 kW (54 hp) of power and 210 Nm (154.89 lb ft) of torque, is integrated into the engine's cooling system.
Energy is stored in a lithium-ion battery system weighing a mere 38 kg (83.78 lb). It is located in a crash-safe area of the trunk and protected by a separate housing. The battery consists of 72 cells; at 266 volts its normal energy is 1.3 kWh and its power 39 kW.
The lithium-ion battery is cooled by air in two ways. At low-temperature load, it draws temperature-controlled air from the vehicle interior by way of a fan. If its temperature exceeds a certain limit, a separate refrigerant circuit is activated. It is coupled to the main climate control system of the vehicle and uses a separate evaporator. This powerful active cooling makes Audi A8 hybrid superior to many other hybrid vehicles.
The exterior of the Audi A8 hybrid has a cohesive, homogenous appearance. The coupe-like roofline with the inclined C-pillars makes the silhouette flow. Sculptured surfaces conveying calmness and prestige contrast with sharp lines. The luxury sedan is 5,137 millimeters (202.24 in) long, 1,949 millimeters (76.73 in) wide and 1,460 millimeters (57.48 in) tall; its wheelbase measures 2,992 millimeters (117.80 in). For the Audi A8 L hybrid, these figures are 5,267 millimeters (207.36 in) long, 1,949 millimeters (76.73 in) wide and 1,471 millimeters (57.91 in) tall. The wheelbase measures 3,122 millimeters (122.91 in).
The single-frame radiator grille of the Audi A8 hybrid is three-dimensional and rich in detail. The standard LED headlights use light-emitting diodes for all lighting functions. They give the sedan a distinctive appearance, do an excellent job of illuminating the road and are highly efficient. The integrated high-beam assistant switches automatically between low-beam and high-beam headlights. The rear lights also feature sophisticated LED technology.
Small hybrid badges on the trunk lid and the fenders indicate the new drive concept. 11 paint finishes are available, with Arctic Silver available as an exclusive option. The engine hood and key of the A8 hybrid also feature a unique design.
Audi has its own unique philosophy when it comes to luxury. Luxury does not mean excess, but rather individual, cultivated style. The selection and workmanship of all materials in the interior of the A8 hybrid are on a hand-built level. The light, elegant interior design conveys the large sedan's athletic character. A large arc - the wrap-around - encircles the cockpit. The front of the instrument panel is in the shape of a gentle wave.
The front seats feature 12-way electric adjustment. Audi also offers a number of seating options up to the comfort sport seats. These can be further upgraded with a ventilation system for the seat surface and backrest, and a massage function with ten air cushions, five programs and five intensities to pamper the back.
The A8 hybrid has clearly structured, intuitive ergonomics. The driver information system with 7-inch screen concentrates all important information and settings in a logical menu structure. The driver can operate it via the leather multifunction steering wheel. The MMI with its elegant, power-retractable 8-inch monitor serves as a second control unit. Its control terminal with the large rotary pushbutton is located on the console of the center tunnel, ideally positioned for the driver's right hand.
The standard three-zone automatic air conditioning enables quiet and low-draft indirect ventilation through a grate on the top of the instrument panel. It controls the temperature of the driver and passenger areas plus the back seat, and offers three climate styles. The ambient lighting, another standard feature, is an artistic overall orchestration of LEDs, light guides and light strips. Many LEDs are two- or three-colored. The driver can use the MMI control system to choose between and make fine adjustments to three different lighting scenarios.
Luxurious: the spacious rear seat
The extended wheelbase of the Audi A8 L hybrid provides for a generous amount of space in the back. Audi offers the option of two power-adjustable and heated individual rear seats. These can also be equipped with optional ventilation and massage functions, and features such as a folding table and a continuous center console make the passengers' journey even more enjoyable.
Audi offers the interior components of the A8 hybrid in a variety of colors. The headlining is available in a choice of three shades. A choice of three grades of leather and a leather/Alcantara combination is available for the seat upholstery. The two-segment decorative inlays are also available in a number of fine materials. The entry sills feature aluminum strips with hybrid logos, and an additional hybrid badge adorns the instrument cluster. A number of additional suggestions for further customization are included in the Audi exclusive program.
The trunk of the Audi A8 hybrid features a luggage capacity of 335 liters (11.83 cu ft) and a low loading lip. As standard, Audi includes a five-piece luggage set designed to optimally fill the available space. The trunk lid opens automatically when unlocked, and a power-assisted function helps to close it. Foot control of the trunk lid is available as an option.
Driver assistance systems
The Audi A8 hybrid can be optionally equipped with a series of assistance systems that make driving even more relaxing and composed. Audi side assist, whose radar sensors monitor what is happening behind the car, warns the driver of critical lane changes. It is activated upon reaching 30 km/h (18.64 mph).
Audi lane assist, which is active at speeds of about 65 km/h (40.39 mph) and above, uses a camera to observe the lane markings. If the driver approaches one of them without using the turn signal, there is an adjustable vibration at the steering wheel. The speed limit display recognizes speed limit signs and presents them on the display of the driver information system and on the MMI monitor. The parking system plus with surround view camera makes parking easier.
Four small cameras monitor the surroundings of the car. A computer combines their images and displays them in a variety of views.
The night vision assistant with highlighting of detected persons uses a far infrared camera that reacts to radiated heat. It displays the information it collects as black-and-white images on the display of the driver information system. The cooler surroundings appear dark, while people and animals are conspicuously bright. The system, which has a visual range of up to 300 meters (984.25 ft), can detect people at up to 100 meters (328.08 ft) away and highlights them with yellow markings. In a hazardous situation, they are marked red and a warning gong sounds.
A standard feature in the A8 hybrid is the safety system pre sense basic. If the ESC sensors report a critical state, the control unit activates the hazard warning lights and closes the side windows and the sunroof, depending on the situation; it also tensions the front seat belts and emits a tone to warn the driver.