Audi Q7 VI2 TDI

When it comes to performance diesels, Audi is king. Its R10 TDI sportscar is tearing up race tracks across the globe, while the R8 supercar will get V12 diesel power in 2010.

However, you won’t have to wait that long to get a first taste of the 6.0-litre powerplant, as it appears in the firm’s flagship Q7 SUV in January. That means the monster seven-seater not only has the biggest diesel engine available in a production car, but also the most powerful by some margin.

As well as using the R8’s motor, the Q7 benefits from technology found in the R10 Le Mans car. The performance statistics are as impressive as its heritage, too. The 6.0-litre V12 delivers 493bhp, and the torque output is an enormous 1,000Nm! These figures mean the two-and-a-half tonne SUV manages to accelerate from 0-62mph in 5.5 seconds – and it feels even faster than that!

Turn the key, and the V12 lets out a deep rumble comparable to a petrol V8. And with all 1,000Nm of torque available from as low as 1,750rpm, even the lightest prod of the accelerator results in instant thrust.

Due to the huge amount of power available, the needle of the rev counter seems to hit the limiter in no time, resulting in the need for constant gearchanges using the six-speed Tiptronic auto. The manic Q7 isn’t without its faults, though. Turning into corners with any speed betrays its weight, and grip suffers as a result.

The steering doesn’t inspire much confidence, either, as it lacks feel. The ride, however, is smooth and comfortable.

Inside, it’s hard to fault the luxurious cabin. The driving position is high, commanding and comfortable, with well placed switchgear and first-rate quality. All this luxury and performance comes at a premium, though. The V12 Q7 costs £96,295 – nearly twice the price of the V8 TDI model below it! It’ll certainly be exclusive, however, as Audi only plans to sell 40 in the UK.