Audi refers to its new V12 TDI turbodiesel as "majestic", but somehow, that word fails to adequately describe the company's latest oilburner. Grammy-winning singer Seal was on hand to belt out his hit "Crazy", and that term more accurately describes a 6L diesel that makes 500 HP and 737 lb-ft of the twisty stuff (that latter number is maintained in the useful range of 1800- 3000 RPM). This is accomplished via a pair of variable-vane turbochargers that apply 1.6 bar (24 PSI) of squeeze to the intercooled intake charge, and a direct injection system which employs piezoelectric injectors to spray fuel - including multiple pre- and post-combustion events - at a mind-boggling 2000 bar (30,000 PSI). A compression ratio of 16:1 and heavy use of exhaust gas circulation also help keep down the emissions, which meet the 2010 Euro-5 standard.

All that power is fed to an all-wheel-drive system that maintains a 40:60 front-rear balance to maintain what Audi refers to as "slightly tail-heavy, sporty handling characteristics. To slow nearly three tons of mass moving at superlegal velocities, a set of monstrous disc brakes are fitted (the diameter is unspecified, but the fronts appear to be somewhere north of 15"). The concept also carries an interior trimmed in impractical white leather and light-colored carbon fiber.

No word as to when it might be produced, which is just as well since we won't be able to afford it.

A time of 5.5 seconds for the sprint from a standstill to 100 km/h and an electronically governed top speed of 250 km/h put the performance SUV from Audi on a par with high-calibre sports cars. The engine limits its consumption to an average of just 11.9 litres/100 km.

The new V12 TDI is the crowning glory of an engine line-up brimming with dynamic performance – each and every one of the diesel engines from Audi generates a high output and tremendous pulling power for a sporty drive. This character has emerged over and over again in the brand's models, not least in the form of the six- and eight-cylinder 2.7 TDI, 3.0 TDI and 4.2 TDI models.

The pioneering role that Audi assumes in the field of diesel technology stems from the peerless expertise it has amassed over a period of decades. Since the 1970s, the Audi engineers have been responsible for one vital breakthrough after another, the most important being the world's first ever TDI engine to be fitted in a passenger car which made its debut in 1989. And in 2008, Audi intends to start making inroads into the diesel market with Bluetec technology: thanks to Bluetec, TDI models bearing the four-ring emblem are not just sporty and economical, they can also run so cleanly that they comply with the emissions legislation in all 50 states.

A year ago, Audi added yet another new chapter to the ongoing diesel success story on race tracks around the world. Developing over 650 bhp, the V12 TDI fitted in the R10 TDI sports prototype left its petrol-powered rivals trailing in all of the races it participated in, including the most challenging of them all, the classic Le Mans 24 Hours. The R10 TDI also triumphed in the LMP1 category of the American Le Mans Series with an impressive string of victories.

The V12 TDI – the new flagship V engine

When working on the road-going version of the V12 TDI, which will be built in its Györ plant in , Audi drew on all of the know-how that underpins the racing engine. The range-topping diesel is the new flagship model in the Audi range of V engines, spanning petrol and diesel units with 6, 8 and 10 cylinders.

The V12 TDI's cylinders actually sweep a greater volume than the racing engine, which has a capacity of 5.5 litres. Its 5,934 cc are produced by a bore of

83.0 millimetres and a stroke of 91.4 mm, the same dimensions as the six-cylinder 3.0 TDI. The two banks of cylinders are positioned opposite one another with an offset of 17 millimetres. Measuring just 684 mm long, the V12 diesel has an extremely compact design. Indeed, its compact size was one of the key prerequisites for integrating the V12 into the Audi Q7.

The V12 TDI features the same 90 mm spacing between cylinders as the other models in the V engine series. However, the cylinder banks are placed at an angle of 60 degrees to one another instead of the customary 90 degrees. This particular V12 configuration suppresses all of the inertial forces and mass moments which would otherwise cause vibrations. Consequently, the engine's smoothness is flawless in every regard.

Article key : Audi Q7 V12 TDI, Audi Q7 V12, Audi Q7, Audi, 2008, 2009
 

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