A8 D4

The A8 was completely redesigned and extensively re-engineered for its fourth generation, gaining around 49mm in the wheelbase, 75mm in length, 16mm in height and 55mm in width.

Audi AG in Germany expected the A8 to start making the same sort of inroads in its Upper Large segment as the A3, A4, A5 and TT have in their respective classes.

It launched in Australia with just the 4163cc petrol V8, which developed 273kW at 6800rpm, 445Nm at 3500rpm and conumed premium unleaded petrol at a rate of 9.5L/100km (13 per cent less than its predecessor) while pumping out 219g/km of CO2. Besides quattro, all Australian-bound A8 models included a new ZF eight-speed Tiptronic automatic transmission and air suspension.

In February 2011, two diesel engines joined the line-up – an evolution of the D3's 4134cc common-rail direct-injection turbocharged engine delivering 258kW of power at 4000rpm and 800Nm of torque from between 1750 and 2750rpm.

A 19 per cent fuel consumption drop has been achieved in the new diesel by Audi’s engineers – partly due to the new gearbox. It used 7.6 litres per 100km on the Australian combined average cycle, could hit 100km/h from standstill in 5.5 seconds, and emitted 199 grams per kilometre of carbon dioxide.

An A8 3.0 TDI quattro became the entry-level variant, powered by a 2967cc common-rail V6 turbo-diesel producing 184kW and 550Nm, returning 6.6L/100km, capable of 0-100km/h in 6.6 seconds and releasing 174g/km of CO2.

A long-wheelbase version, unveiled at the 2010 Beijing motor show, was also added to the range, available with all engines.

4.2 TDI quattro and 4.2 FSI quattro models will include LED driving lights, 22-way adjustable front seats, a ‘sport’ differential (that varies the amount of torque allocated between the rear wheels), an interior ambient lighting package and MMI Navigation Plus satellite-navigation.

Also standard was Audi's MMI Touch hand-writing recognition system for the sat-nav and phone applications.

The D4's silhouette boasted a more coupe-like profile, a visibly lower bonnet and boot line, and a more road-hugging stance. It also aided aerodynamics, with a class-leading 0.26Cd drag co-efficient (down from 0.31Cd in the D3), leading Audi to claim the newcomer as the quietest in its class, with no wind noise evident at 120km/h.

Under the all-aluminium skin Audi adopted the existing B8 A4/A5 range’s five-link front suspension system instead of the old model’s MacPherson strut arrangement.

Revisions could also be found in the multi-link rear suspension set-up, which also brought extensive weight reductions thanks in part to the fact all wheel control arms were made of aluminium.

The D4 A8’s Drive Select function could vary the damping, throttle and steering rates, while the optional Dynamic Steering system altered the hydraulic system’s turning ratio according to speed of the car.

Audi’s ‘Pre Sense Safety’ technology would prepare the vehicle’s various safety systems for either improved accident avoidance or impact mitigation. Meanwhile, latest-generation night-vision technology was able to detect and single out pedestrians at up to 300 metres away.

Twin 10.2-inch rear-seat entertainment screens and a 1400-Watt 19-speaker Bang and Olufsen sound system could also be ordered on the Audi flagship.

Finally, the boot, rated at 510 litres, could accommodate four golf bags, offered side compartments for smaller objects, and could be had with a load-through ski-bag.