The sportiest premium sedan in the full-size class – the new Audi A8
The Audi A8 L W12
The long-wheelbase Audi A8 L W12 stands at the head of the new A8 model family. It features an exclusive powerplant. The W12 gasoline engine produces 368 kW (500 hp) and delivers 625 Nm (460.98 lb-ft) of torque at 4,750 rpm. The sprint from 0 to 100 km/h (62.14 mph) is completed in 4.6 seconds; the electronically governed top speed of 250 km/h (155.34 mph) is just a formality. Average fuel consumption of the highly cultivated twelve-cylinder is 11.3 liters per 100 kilometers (20.82 US mpg), corresponding to CO2 emissions of 264 grams per kilometer (424.87 g/mile).
Displacing 6,299 cc, the W12 engine is barely over 50 centimeters long and roughly 70 centimeters wide and tall. It consists of four rows of three cylinders. Two rows face each other in a mutually offset configuration at 15-degree angles, respectively, and collectively form a single broad bank. The two cylinder banks thus form a 72-degree V configuration. The crankshaft has a crankpin offset of twelve degrees so that the twelve cylinders ignite in the ideal interval of 60 degrees.
Weighing 234 kilograms (515.88 lb), the W12 engine is relatively lightweight. Its crankcase is made of a high-strength, lightweight aluminum-silicon alloy, with a traverse with embedded cast iron bearing seats forming the bottom. Due to the V-position within the cylinder banks, the pistons, which are also made of a lightweight alloy, have beveled surfaces in order to create combustion chambers with optimized geometry for maximum efficiency. The crankshaft drive and chain drive have been optimized for minimal friction, and the thermal management system distributes the heat flows between the engine, transmission and interior.
Rotating inside the aluminum cylinder heads are four camshafts, which can be moved through 52 degrees of crankshaft motion. Chain-driven, they actuate the 48 valves via roller cam followers. The fuel flows directly into the combustion chambers, and the shape of the intake ports imports a rolling motion to the inflowing air. Together with the high compression ratio of 11.8:1, this “tumble” also increases efficiency.
New in the W12 is the efficiency technology cylinder on demand (COD). At low to intermediate load and engine speed, such as 250 Nm (184.39 lb-ft) at 3,000 rpm, it shuts down the cylinders of the left or right bank when in the upper four gears by deactivating the injection and ignition. In the event of a lengthy deactivation phase, the cylinders in the deactivated bank are fired to prevent their catalytic converter from cooling off. The cylinder banks are thus deactivated in turns during extended periods of COD operation.
Design: Understated appearance
Understated visual clues reveal the identity of the Audi A8 L W12. The bars in the Singleframe grille are wider at the corners, and chrome honeycomb grilles are mounted behind it and in the air inlets. W12 badges shine from the grille, the flanks and the back of the car.
The top-of-the-line A8 features brakes with six-piston calipers up front. Size 255/45 tires are mounted on 19-inch wheels. The tires include “torus absorbers” – foam strips between the running surface and the carcass that dampen the noise generated in the torus (annular body) of the tire when rolling. Optional 20-inch wheels with a 15-spoke structured design are exclusive to the A8 L W12.
The Audi A8 L W12 comes with a very luxurious array of standard equipment. Examples include Matrix LED headlights, ambient lighting, power door closing, comfort seats up front and individual rear seats with comfort head restraints, grab handles with wood segments (piano finish), make-up mirror and separate reading lights. There is also the extended leather and an Alcantara package, inlays in piano finish and aluminum, four-zone automatic air conditioning, the parking system plus with reversing camera, MMI navigation plus with W12-specific welcome screen and Audi connect including car phone with separate handset. A cell phone holder is located in the pocket in the right rear door.
For customers looking for something very special, quattro GmbH offers the A8 L W12 Audi exclusive concept, which is limited to a run of just 50 units. Leather from the Italian furniture manufacturer Poltrona Frau in the color Agatha cognac dominates the interior. Its gently treated surface is velvety soft. The inlays are made of the rare veneer fine grain olive ash natural silver brown with silver pigments as pore filler. Its gray-brown shade harmonizes with the granite gray piping on the seats. The headlining is snow white.