liter diesel V12
lb-ft @ 1750 - 3000 rpm
hp per liter
mph (electronically limited)
(from Audi Press
Release) The World’s Most Powerful Diesel Passenger Car
Audi has stood at the forefront of diesel technology for the last
three decades. The Ingolstadt brand now presents a further world
first – the first V12 diesel engine in a passenger car. The new Audi
Q7 V12 TDI is powered by a twelve-cylinder diesel engine containing
a wealth of pioneering technology. With an outstanding 500 PS and
1,000 Nm of torque, the six-litre engine of the high-performance SUV
provides the driving performance of a sports car.
Sprinting from 0 to 100 km/h in just 5.5 seconds and achieving an
electronically governed top speed of 250 km/h, the Audi Q7 V12 TDI
is catapulted into the echelons of top-class sports cars. New
horizons have been set in the diesel market thanks to this
outstanding power. None of our competitors can offer a comparable
The big performance SUV from Audi accelerates with impressive ease.
Superior power reserves in any situation are provided by the world’s
first 2,000 bar Bosch Common Rail system. The ultra-modern
piezo-injection system offers impressive acoustics at the highest
levels of driving comfort.
The new six-speed tiptronic gearbox, which features extensive
reinforcements, shifts quickly and comfortably. It transfers the
enormous power to the quattro permanent four-wheel drive system. The
new Audi Q7 V12 TDI has an average fuel consumption of just 11.9
litres per 100 kilometres.
All diesel engines from Audi are highly dynamic thanks to their high
performance and high torque characteristics. Audi has often proved
its sporty character in series production, most recently through the
six and eight-cylinder 3.0 TDI and 4.2 TDI engines. Audi also
rewrote the record books earlier this year on the racetrack.
Following its debut in Sebring, Florida, the premium R10 prototype
sports car won every long-distance race it entered.
These included the Le Mans 24 Hours road race, probably the most
difficult race in the world for both man and machine.
The V12 race engine in the R10 squeezed 650 bhp from its 5.5-litre
engine capacity, reaching a top speed of 330 km/h. The power and
endurance of the R10 was an immediate hit with fans and experts
alike. However, what completely surprised them was the sound of the
engine: unlike most racing engines, the powerful Audi diesel engine
Transferring race car technology into series production is an Audi
tradition. The FSI engine in the predecessor to the R10, the R8,
notched up five victories in Le Mans with its petrol direct
injection. Audi has already transferred FSI performance to the
production line. The most recent examples of this are the
high-revving V8 in the RS 4 and the V10 FSI in the S6 and S8.
Pioneering technical performance
The new series-production V12 TDI, assembled in our plant in Györ,
Hungary, reaches a still outstanding level of “only” 500 bhp. When
designing the engine, it was kept in mind that the six-litre engine
would be a derivative of the current family of Audi V-engines, which
up to now were limited to six, eight and ten cylinders. The basic
findings from the race car were of course transferred to the
series-production engine. The V12 TDI aggregate has a cylinder
90 mm, which is standard for engines of this type. Nonetheless, the
engine has a cylinder angle of 60° instead of 90°, leading to an
elimination of inertia in this type of V12 design. Driving comfort
is thus ensured in every situation.
The total engine capacity of 5,934 cm3 is derived from a bore
measurement of 83 mm and a stroke of 91.4 mm, exactly the same as
that of the 3.0 TDI. The large diesel engine is extremely compact.
Measuring 684 mm in length, it is only 166 mm longer than the V8
TDI. These dimensions are the primary requirement for integrating
the V12 into the Audi Q7.
The crankcase of the V12 TDI is constructed from cast-iron with
vermicular graphite. This high-tech material, known as GJV-450, has
already been used in the V6 and V8 models.
Produced in a patented casting procedure, GJV-450 is around 40 %
more rigid and 100 % more fatigue-resistant than grey cast iron.
This allowed the developers to reduce the wall thickness. The weight
potential compared to conventional grey cast iron is around 15 %.
The crankshaft, forged from a chrome and molybdenum steel alloy, is
held by an extremely rigid main bearing bracket made from cast iron
reinforced by nodular graphite. The forged piston rods are cracked,
whilst the forged pistons are made from aluminium.
Both cylinder heads are composed of three main elements. The lower
section is made from a highly durable and light aluminium alloy
where the intake and escape channels are integrated. The upper
section guides the flow of engine oil, whilst both camshafts are
stored within a reinforcing ladder frame.
The valves are actuated using low-friction roller cam followers with
a compression ratio of 16:1. The engine characteristic swirl
variations of combustion air were taken from the V6 and V8 TDI
engines. The optimum swirl with respect to emissions and
simultaneous high performance can therefore be set.
Ultra-modern injection technology
Like most Audi V-engines, the maintenance-free chain drive is
located on the back of the engine in a space-saving arrangement. A
new layout is used in the new V12 TDI. The chain wheel of the
crankshaft locks into the gearwheel. From here two simplex chains
drive the camshaft. Two further chains drive the oil pump and both
high-pressure pumps in the common rail injection system.
Both new double stamped high-pressure pumps are part of the new
common rail injection system developed by the specialists at Bosch.
Both pumps amass up to 2,000 bar of pressure in the rails; only
1,600 bar was usually achieved up to now.
The piezo injectors, with their eight-hole jets, have also been
radically updated.An optimal spray is created in the combustion
chamber through the high pressure. This in turn allows the ignition
process to take place quicker and more homogenously, leading to a
much better sound. The efficient combustion also improves
performance whilst reducing emissions and fuel consumption.
The current generation of inline injectors use the piezo effect.
When an electric current is created, piezo crystals expand in
milliseconds. This expansion is then directly transported (inline)
by the V12 TDI injectors – containing over one hundred piezo plates
– to the injection nozzle needles without the use of mechanisms in
The number of injection processes per power stroke can be widely
varied using piezo technology, in the case of the V12 TDI up to five
In addition to the main injection, pre and post-injections are
possible. Pre-injections reduce the acoustic hardness of the
combustion procedure. Post-injections serve to increase the
temperature of the emissions, helping regeneration of both
standard-fit particulate filters.
Both turbochargers can be found on the exterior of the V-engine,
each supplied with a cylinder bank. Thanks to its adjustable guide
vane geometry, the complete gas emission stream is always fed
through the turbines. The chargers respond even at low levels of
revolution and reach high levels of efficiency.
Both turbochargers amass a charge pressure of up to 2.6 bar and are
a key aspect of the exceptional torque levels of 1,000 Nm that are
supplied to the V12 TDI constantly between 1,750 and 3,000 rpm. With
its 368 kW (500 bhp), the diesel reaches a specific performance of
62 kW (84.3 bhp) per litre of engine capacity.
Two large charge air coolers reduce the temperature of the
compressed air. The V12 comes with a double-flow exhaust system with
two particulate filters. The suction unit is built in a similar way
– each cylinder bank contains an air filter behind which an air mass
meter is stored. Two control units manage what happens within the
engine according to the master-slave concept.
The Audi Q7 V12 TDI will conform to the Euro 5 emissions class which
will come into force in 2010 and demand a reduction of nitrogen
oxide emissions. Aside from the precise analysis of the fuel
injection system through the common rail system, the Audi engineers
have focused especially on exhaust gas recirculation. At partial
load, up to 50 % of emissions are recirculated through the air
intake in order to reduce nitrogen oxide emissions. The
large-dimension recirculation system is stored in the upper section
of the V cylinder and includes a water cooler which reduces emission
The Audi Q7 V12 TDI is impressive not only with regard to technology
but also in terms of appearance. The most striking visual changes to
the Audi Q7 are the underbody panels at the front and rear. The
chrome-plated single-frame radiator grille evokes the tradition of
the Audi S6 and S8. These two cars, with their
V10 FSI engines, are the top sports models in their class. The V12
TDI features a powerful braking system which is every bit its equal.
Diesel milestones from Audi
A further milestone in diesel technology has been reached with the
advent of the new V12 TDI. The Ingolstadt brand has been the pioneer
in the diesel domain for over three decades. The first TDI engine in
motoring history was introduced in the Audi 100 in 1989. The
2.5-litre five-cylinder engine offered 88 kW (120 bhp) and 261 Nm of
torque, and catapulted diesel motoring into whole new dimensions.
In 1994, an expanded version was produced with 103 kW (140 bhp). The
engine was also available with the option of four-wheel drive – the
first TDI quattro. At the same time, a new four-cylinder diesel
engine was introduced in the Audi 100 and Audi 80, the now legendary
1.9 TDI with 66 kW (90 bhp).
Towards the end of 1995, the four-cylinder achieved new heights of
85 kW (115 bhp) through the use of pump-jet injection. Just over a
year later at the beginning of 1997, the world’s first 2.5 V6 TDI
made its debut. This engine came with four valves per cylinder and
reached 110 kW (150 bhp). With a top speed of 220 km/h the Audi A8
became the quickest series-production diesel on the market. The
first eight-cylinder TDI followed in 1999, a V8 with a displacement
of 3.3 litres. The 3.0 TDI was introduced in the spring of 2004, the
first V6 diesel engine with inline piezo injectors in the common
The 4.2-litre TDI currently spearheads the TDI range from Audi. It
was first introduced last year in the A8. Every third A8 buyer in
Germany decided opted for the V8. The V8 TDI will also become
available for the Audi Q7 during the first half of 2007.