Bucking the trend for incrementally expanding replacements, the new A6 is slightly shorter than the outgoing car, with a lower roofline. It is, however, wider than its immediate forebear and, courtesy of Audi’s MLP platform, has a shorter front overhang and longer overall wheelbase than the last A6. This makes for greater legroom and shoulder room throughout the cabin, as well as a more optimal weight distribution.
See pics of the Audi A6 in development
Although it’s fitted with more electronic sub-systems as standard, Audi’s new A6 is 80kg lighter than its antecedent, model for model. Wider use of aluminium in the hybrid aluminium/steel superstructure means that the new car’s body-in-white is now 20 per cent aluminium and weighs 15 per cent less than it would if constructed exclusively from mild steel. The car’s doors, wings, bonnet, bootlid and bumpers are also aluminium.
There will be four engines to choose from when the car enters the UK market in April and there could be as many as five more in the pipeline. The launch offering will start with a 175bhp, 280lb ft 2.0-litre TDI — the likely fleet-favoured volume seller. Equipped with a six-speed manual ’box, it will be good for 62mph in 8.7sec but will emit only 127g/km of CO2 and should consume just 57.5mpg on the combined cycle.
Two other diesel versions of the A6 will be offered in the UK, both using Audi’s new 3.0-litre common-rail V6. The detuned 202bhp version will be offered with Audi’s optional Multitronic continuously variable transmission and front-wheel drive. It emits 137g/km of CO2 and returns 54.2mpg.
The higher-output 243bhp V6 diesel will get quattro four-wheel drive and Audi’s seven-speed S-Tronic twin-clutch gearbox. With 369lb ft of torque from 1400rpm, it should crack 62mph in 6.1sec, consume an average of 47mpg and emit 157g/km of CO2.
Read more on the strong demand for Audi's range in the UK
This fourth-generation A6 breaks the mould by being launched without an eight-cylinder petrol engine. Although other markets will be offered a 202bhp 2.8-litre normally aspirated V6 FSI as well, the only petrol A6 on offer in the UK will be a 3.0 TFSI with 298bhp, 325lb ft of torque, quattro four-wheel drive and a seven-speed twin-clutch gearbox.
Optional S-Line suspension honed by Quattro GmbH and a sports styling kit will give owners the opportunity to add somedynamism to the flagship A6, which should hit 62mph in 5.5sec and a limited 155mph. However, a faster V8-powered S6 will be along later.
For those more impressed by economy, a hybrid petrol-electric A6 will be launched in 2012, using a powertrain adapted from that of the Q5 hybrid (see below). However, it will emit a relatively unremarkable 142g/km of CO2 and return 45.6mpg, so it’s unlikely to attract the attention of those looking for a really frugal alternative in Europe.
A low-CO2 diesel version of the A6 is under consideration. It could come to the market midway through the A6’s life and offer sub-120g/km and 60mpg-plus fuel consumption. “We know how important CO2 emissions can be for fleet buyers in some markets, and we can be responsive about such a car if the demand arises,” an Audi spokesman told us.
Read Autocar's road test on the new Audi A8 saloon
Several measures have combined to make the new A6 up to 19 per cent more fuel-efficient than the outgoing model. A drag coefficient of just 0.26 minimises both aerodynamic resistance and wind noise. The car features engine stop-start as standard, as well as all of the economy-boosting technologies that Audi collects under its ‘recuperation’ banner.
Twin-clutch gearboxes have replaced less efficient torque converter autos on the higher-powered models. This A6 is also only the second longitudinally engined Audi, after the A7, to get more efficient, fully electric power-assisted steering.
Lightweight aluminium chassis arms form part of the new A6’s suspension, which consists of a five-arm double wishbone-like arrangement up front and more conventional trapezoidal multi-links at the rear. Steel springs come as standard and are available in the incrementally stiffer tunes of standard, Sport and S-Line. Air springs are available as an option.
Audi will also fit a new five-mode Audi Drive Select system on the new A6, with which drivers can tailor the power steering assistance, throttle response and drivetrain settings to suit their tastes.
The Comfort, Auto, Individual and Dynamic modes will be familiar to current Audi A8 owners, while a new Efficiency mode sets up all of the A6’s adaptable systems for optimum economy.
Read Autocar's first drive of the new Audi A7 Sportback
See all the latest Audi A6 reviews, news and video