Audi, the inventor of TDI technology, is penning a new chapter in the history of diesel engines with the Audi Q7 V12 TDI quattro. The world's first V12 diesel engine in a series-production vehicle moves this big, high-performance SUV with supreme confidence and composure. On demand, the six-liter engine catapults the Audi Q7 from zero to 100 km/h (62.14 mph) in 5.5 seconds like a top-class sportscar. Speed is electronically capped at 250 km/h.
The 12-cylinder diesel engine is no less impressive when it comes to fuel consumption. On average, it requires just 11.9 liters of fuel per 100 km (19.77 mpg), a surprisingly good figure in light of the strength of the engine. The six-liter TDI uses significantly less fuel than any competing gasoline engine in the high-performance SUV sector; thanks to efficient combustion and the complex exhaust emission control system, the Audi Q7 V12 TDI quattro already complies with future emissions standards.
Totally refined, high-tech engine
The V12 TDI captivates its drivers with sheer inexhaustible power and highly cultivated operation – the subtle engine sound takes on a voluminous, strong note when the throttle is open. The six-liter unit is a member of the modern family of Audi V engines, all of which have center-to-center spacing of 90 millimeters between cylinders. Instead of the usual 90 degrees, however, its cylinder angle measures 60 degrees. This method of construction is ideal for the V12 as it prohibits any undesirable free inertial forces and moments of inertia.
Another factor contributing to the vehicle's smooth running characteristics is the high rigidity of the crankcase. Made of cast vermicular graphite, it is approximately 15 percent lighter than conventional gray iron. The six-liter unit is extremely compact at just 684 millimeters in length. The crankshaft is held in place by a rigid main bearing bracket. The V12 TDI's engine capacity of 5,934 cc is derived from a bore measurement of 83.0 millimeters and a stroke of 91.4 millimeters, just as in the 3.0 TDI.
The aluminum cylinder heads consist of three elements: the lower section where the intake and escape channels are integrated, the upper section which guides the flow of oil and a reinforced ladder frame containing the two camshafts driven by two simplex chains on the back of the engine. The valves are actuated by low-friction roller cam followers. Map-controlled flaps in the intake channels cause the induced air to swirl. This improves combustion, thus reducing emissions and enhancing performance.
High pressure: 2,000 bar in the common rail system
The common rail injection system, with high-pressure pumps driven by chains, can create pressure of up to 2,000 bar. The high pressure level permits intensive mixture formation of the fuel in the combustion chamber, thereby facilitating especially smooth, acoustically satisfying combustion. Shifting very rapidly and precisely, the eight-hole injectors working on the piezo principle can deliver up to five injections per combustion cycle.
Two turbochargers are positioned on the exterior of the V engine, each supplied with a cylinder bank. Thanks to their adjustable guide vane geometry, they respond quickly even at low engine speeds and reach high levels of efficiency, applying a relative maximum boost pressure of 1.6 bar. Two large charged air coolers reduce the temperature of the compressed air, paving the way for the high output of 500 hp.
Outstanding performance paired with exceptional efficiency
The six-liter TDI unit is further impressive proof of the technological leadership embodied in Audi's "Vorsprung durch Technik" slogan. Back in 1989, the brand with the four rings put the TDI principle into series production and has been continually advancing it ever since at the forefront of the field. The most powerful diesel in its class generates an extremely high specific torque of 169 Nm per liter of capacity; 1,000 Nm is available at a range of 1,750 to 3,250 rpm. Specific power output is 84.3 hp – equivalent to that of a sportscar.
The new V12 TDI in the Audi Q7 is closely related to the engine that twice powered the Audi R10 TDI racing car to overall victory in the Le Mans 24 Hours – a 5.5-liter V12 that delivers approximately over 650 hp.
The Audi Q7 V12 TDI quattro's powerful engine torque flows through a rapidly and gently shifting six-speed tiptronic that was specially designed for the six-liter diesel engine's immense torque. The driver can shift the gears of the automatic transmission either with the selector lever or manually with the standard chromed shift paddles on the three-spoke steering wheel.
The quattro drive distributes the power to the front and back wheels in a 40:60 ratio – giving the vehicle a sporty, rear-focused driving style that guarantees maximum agility and driving enjoyment. When needed, the inter-axle differential transfers most of the power to the axle with better traction. Great care has also been devoted to reinforcing all key components in the quattro driveline.
High tech from Audi: The aluminum chassis
The chassis of the Audi Q7 V12 TDI quattro is a marvel of high-tech construction. Elaborate double wishbones guide the front and rear wheels; the axle components are made primarily of aluminum. Thanks to the extreme precision and directness of the servotronic steering, the driver remains in close contact with the road. This is where the handling characteristics, driving safety and comfort of the high-performance SUV set new standards. With maximum ground clearance of 205 millimeters, the Audi Q7 V12 TDI quattro also proves itself easily capable of handling the demands of rough terrain.
The adaptive air suspension works with sporty new tuning. In combination with electronically controlled shock absorbers incorporating dynamic roll stabilization, the air suspension can be adjusted in three zones ranging from extremely comfortable to highly dynamic. The driver can also adjust ground clearance in five stages via this system and lower the tail end by 71 millimeters for comfortable loading.
Standard carbon-fiber ceramic brakes
The ultimate high-performance SUV from Audi takes to the road on sporty 10-spoke wheels of 20 inches in diameter. Alternatively, the wheels are also available in a 20-spoke design or as 21-inch variants in three different designs. Behind the large wheels is a powerful 20-inch brake system. Made of ceramic reinforced with carbon fiber, the internally ventilated disks are notable for their low weight, robust performance and minimum wear. The front disks are gripped by eight-piston brake calipers, while the rear brakes function with four pistons each. The calipers are titanium gray and the front ones bear the "Audi ceramic" logo.
The visual styling of the Audi Q7 V12 TDI quattro gives it an unmistakable look. Daytime running lights consisting of twelve white LEDs per headlight announce the vehicle's presence even at a distance. They are located on the upper edge of the air intake slots, replacing the turn signals that were moved to the bi-xenon headlights. Further honing the vehicle's profile is a chromed grid in the single-frame radiator grill and a shiny underbody protector made of stainless steel. The newly designed bumper groups the side air intake slots into large units.
When viewed from the side, both the 20-inch wheels and the matt aluminum caps on the exterior mirrors catch the eye. The wheel arches have been widened a total of 26 millimeters at the front and 30 millimeters at the rear; the lower edges of the doors flaunt striking new moldings. The windows are framed by matt aluminum cover strips, the roof rails sport the same look. The taillights are set in a dark-colored background, while the newly designed bumper incorporates two large, oval exhaust tailpipes. At the rear, the underbody protector is also made from stainless steel. A metallic or pearl effect finish comes standard.
Sophisticated: Highlights on board the Audi Q7 V12 TDI
In the interior of the most powerful Audi Q7, passengers will find shiny door sill trim with aluminum inserts and velours carpet. Carbon covers and the aluminum-look selector lever give the center tunnel a high-tech ambience, exclusive wood trim is available as an option. The buttons of the MMI operating system, which has proven a superior concept in numerous independent tests, gleam in silver, the air vents in aluminum, the pedals and footrest in stainless steel. On the speedometer, the range extends up to 310 km/h.
Verano leather covers the electrically adjustable sport seats, the deluxe center armrest and the armrests in the doors are upholstered with leather as well. The front and rear seats can be heated; a special lighting package softly illuminates the interior.
Also included in the luxurious standard specification are the leather package, leather multi-function sports steering wheel, black roof lining, folding exterior mirrors, DVD navigation system, Bose Surround Sound system with CD changer, Bluetooth mobile phone preparation, alarm system and tire pressure monitoring system. The tailgate opens and closes electronically. Partially overlapping the D-pillars, it gives the vehicle a brawny rear body.
There are four optional high-tech assistance systems for the Audi Q7 V12 TDI quattro: The adaptive cruise control system, Audi lane assist and Audi side assist aid the driver in maintaining the proper distance to the vehicle ahead, staying in lane and changing lane, while Audi parking system advanced incorporates a camera for a clear view behind the vehicle.
The optional Audi music interface offers a convenient iPod interface. Available on request, the B&O Advanced Sound System creates an unparalleled acoustic experience. An even more comfortable interior can be achieved with the advanced leather package that includes, among other things, exclusive leather covering of the instrument panel and center console.
The large glass roof open sky system is available to crown the spacious interior – optionally with four, five, six or seven variable seats – as is a rail system for the cargo area of up to 2,035 liters in size.