The Audi Q7 V12 TDI - the world’s most powerful diesel passenger car
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Image Gallery ( 3 images )September 15, 2006 Audi is set to debut the first twelve-cylinder diesel engine in a series passenger car. A six-litre V12 will be available in the Audi Q7 that is reminiscent of the engine featured in the all-conquering R10 Le Mans racing car and it catapults the driving performance of the Audi Q7 SUV into the echelons of top-class sports cars. The V12 TDI engine produces a colossal 500 PS and 1,000 Nm of torque giving the car a 0 to 100 km/h time of just 5.5 seconds, and an electronically governed top speed of 250 km/h. Maximum torque is available from just 1,750 rpm. The high-tech diesel engine, with the world’s first 2,000 bar Bosch Common Rail system, provides the high-performance Audi SUV with superior power reserves in any situation. The impressive sound of the new Audi is provided by the ultra-modern piezo-injection system. The V12 TDI transmits this power through a new six-speed tiptronic gearbox to the quattro permanent four-wheel drive system.
Although the V12 TDI belongs to the Audi V-engine family, this model features a special cylinder angle of 60° – perfect for this engine type. Apart from the light and highly durable crankcase, a further highlight is the new chain drive assembly. This includes the two newly developed high-pressure pumps in the common rail injection system.
Up to 2,000 bar of pressure is kept within the twelve piezo injectors – a further technological breakthrough. Both performance and efficiency are optimised by this high injection pressure, and the running smoothness also remains excellent. Exhaust emissions are also low. The twin-turbo V12 TDI conforms to the Euro 5 emissions class which should come into force in 2010. Fuel consumption is only 11.9 litres per 100 kilometres. With the high-tech twelve-cylinder engine using TDI technology, the diesel pioneers at Audi have opened new horizons in motoring.
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.
Audi rewrote the diesel 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, where 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. What completely surprised fans and experts alike however, was the sound of the engine: unlike most racing engines, the powerful Audi diesel engine runs whisper-quiet.
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.
The new series-production V12 TDI, assembled in Audi’s plant in Györ, Hungary, reaches a still outstanding level of 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 clearance of 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.
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