Audi A8 2007 Review

Audi's oil-burning twin turbo V8 is a fantastic advertisement for what diesel has to offer. The big 4.2-litre common rail direct injection diesel generates 240kW of power and 650Nm of torque from a low 1600rpm.

That's enough oomph to push Audi's flagship A8 from rest to 100km/h in a super quick 5.9 seconds. That's faster than the 3.2 and 4.2 petrol models. And, if the wind's blowing the right way, it even sounds like a V8 although somewhat subdued.

The punchline, however, is that it can do this at the same time as using just 9.7 litres of diesel/100km. With a 90-litre fuel tank, that gives the A8 TDI a range of more than 900km.

But it's not just about the economy, it's about the way the big diesel drives because, with all that torque, it delivers effortless performance.

Each of the two turbochargers serves one bank of the V8's eight cylinders. The two intake manifolds are interconnected by means of a 'feedthrough' system, to equalise the pressure between the right and left cylinder banks.

Audi claims this boosts cylinder charging and consequently enhances the engine's power output.

We can't argue with that.

Sitting long and low, the lightweight, aluminium-bodied A8 cuts an imposing figure. It looks like the kind of car you'd own if you had money, but didn't have the time to waste on some antsy pantsy sports car.

At $210,000, the A8 4.2 TDI Quattro is at the top end of town. But even at this price it still falls a long way short of the $300,000 top of the range long wheelbase W12.

The V8 is hooked up to a six-speed tiptronic automatic transmission with dynamic gearshift program and additional sports program. Let it change gears, or do it yourself via the gear shift or steering wheel mounted paddles.

Power is delivered to all four wheels via Quattro permanent four-wheel, with anti-lock brakes and Electronic Stability Control.

The A8 is 5062mm long, 1894mm wide and 1444mm high. It weighs in at 1945kg and sits on 19-inch alloys with 255/40 rubber.

For a big car it responds quickly with strong performance across the range, doing a good job of living up to Audi's 'world's sportiest' diesel-engined passenger car claim.

Topping off the package is adaptive air suspension, which allows you to dial in the kind of ride you want - from soft and cushy to firm and sporty.

We could live without the wood (it does come in grey) but miss exterior mirrors that dip when reversing.

The TDI's equipment list is as long as your arm. Leather, wood and plenty of airbags are standard, so is TV, Satnav and a cordless phone.

But even at this price there are still plenty of options, from sports suspension to a reversing camera and adaptive cruise control.