Audi has pushed its A8 sedan right into the limousine class with the all-new model for 2010. We found its refinement, smoothness and near silence outstanding during our road test review in the north of Australia out of Cairns.

The A8 is larger than ever before and has good interior space for four adults. However, the rear seat may prove tight if all four are lanky Aussies. To cater for these people, as well as for the limousine fleet, a long-wheelbase version of the A8 will be released later.

Even the standard-wheelbase A8 shows intelligent design in its rear seat, with a fold down centre armrest that effectively converts the rear area into twin bucket seats. A fifth occupant can travel in the centre-rear spot without too much compromise.

It almost goes without saying that the design and quality of the Audi A8 interior is close to perfect. Other car marques make no secret of the fact that they strive to equal Audi’s interior. But we have bad news for them – the barrier has been raised yet again.

The cabin’s styling uses an integrated combination of leather timber and alloy that's pleasing to the eye. Combine this with large comfortable front seats that have multiple adjustments and you have a most pleasant place to travel.

Keeping track of your movements, as well as dialling up your choice of entertainment systems is done by a heavily revised version of Audi's MMI (Multi Media Interface). The MMI now includes the intriguing feature of a touch sensitive pad that actually lets you write instructions to the system with your fingertip. For example, this can be used to request an address on the satellite navigation system. We found it to operate very well, though we still recommend you only carry out tasks like this when the vehicle is stationary.

The all-new Audi A8 is powered by a silky smooth V8 engine displacing 4.2 litres. Though this unit is related to the one used in the previous A8 it has been significantly uprated. It now produces significantly more power and torque, yet uses less fuel and produces fewer emissions while doing so.

Peak power is 273 kilowatts at 6800 rpm, with top torque of 445 Newton metres at a reasonably low 3500 revs. That torque figure considerably exceeds the 100 Nm per litre of engine capacity that's often taken as the benchmark for modern engine design.

Acceleration from rest to 100 km/h takes a sportscar-like 5.7 seconds. But there's a lot more to performance driving than simply straight line acceleration and we found the ability of this engine to accelerate the large car exceptional. Particularly in the way it permits safe overtaking on the short stretches of straight road on the drive program mapped out by Audi Australia.

Yet all this performance is achieved in a car with officially rated fuel consumption to Australian standards of just 9.5 litres per hundred kilometres. This is a decrease in fuel consumption of 1.4 litres per hundred kilometres compared with the previous incarnation of the engine in the A8. We should point out that during our hard driving on some demanding roads the fuel figure was generally in the 11 to 13 litre range. But we don’t doubt that 9.5 litres would be there on a gently paced trip.

Part of this excellent economy is achieved by an all-new eight-speed automatic transmission that we found was generally in the right gear. Should you wish to go for semi-manual ratios on the transmission the Audi A8 now has paddles on the steering wheel.

Another reason for the economical running is the continuation of a lightweight aluminium body on the A8 range.

At a recommended retail price of $225,904 (plus on-road costs) the Audi offers good value for money in this upmarket class. Lower cost variants will arrive in Australia later. These are likely to include a V6 petrol engine and V6 and V8 turbo-diesels.