Audi's diesel supercars

Audi is going big on diesel in every respect with the Q7 V12 TDI and R8 TDI Le Mans that both use the same 6.0-litre turbodiesel engine.

The Q7 V12 TDI will be on sale by the end of 2008 with an expected price of £70,000.

For that, customers will have the world's most powerful turbodiesel production car, packing 496bhp and 758lb.ft of pulling power.

This will be enough to get the Q7 from 0-62mph in 5.5 seconds and onto an electronically governed top speed of 155mph.

Audi reckons there will be sufficient demand for a performance diesel SUV and will beat Porsche's hybrid Cayenne into the showrooms.

The Q7 V12 TDI can return 19.8mpg economy and has a six-speed automatic gearbox as standard.

Other standard equipment for the Q7 will include satellite navigation, leather seats, Bose stereo system and 20-inch alloy wheels.

However, the yacht-inspired wooden trim of the Geneva show car is a one-off for the benefit of show-goers.

Also giving visitors to the Audi stand a treat is the R8 TDI Le Mans.

Audi says this car is only a concept, but company insiders strongly hint that a limited number of production models will be sold.

Inspired by Audi's diesel-powered Le Mans winners, the R8 has the same 496bhp 6.0-litre V12 engine as the Q7, but has a top speed of more than 186mph.

This R8 covers 0-62mph in 4.2 seconds and will be offered with a six-speed automatic gearbox.

Audi has had to stretch the R8's curvy bodywork in places to accommodate the V12 engine, as well as extending the wheel arches to cover the massive wheels and tyres.

There are also larger front air intakes, twin rear diffusers to suck the car to the road and a new rear spoiler that adjusts its angle according to speed.

Inside, the R8 TDI Le Mans looks much like other R8 models, but it has a lap timer built into the satellite navigation.

Audi won't be drawn on price or on-sale dates, but expect the R8 TDI Le Mans to cost from £90,000 and be on sale by summer 2009.

Alisdair Suttie

(Additional photographs by United Pictures)