Twin test: Audi A6 vs BMW 5 Series

Few cars are as closely matched as the BMW 5 Series and the new Audi A6. The former has been around for a couple of years already, which means Audi will have bought scores of them to tear down, study in microscopic detail, then simply throw away. Just to make sure its car is objectively better than, or at least as good as the Bavarian equivalent. So the new A6 should be hands-down better than its rival. Only it’s not. Allow us to explain…

Audi’s new A6 shares a platform with the A8 and A7. That makes it bigger than the car it replaces by 7mm in length, 12mm in width and 2mm in height. And while there’s undoubtedly a lot of A4 and A8 going on in the design – because why wouldn’t there be? – it’s a quietly handsome thing. Especially in S Line trim, which adds a pinch of aggression to a car you might otherwise accuse of being a bit bland. It’s certainly better-looking than the 5 Series, which is downright ugly. Even in M Sport spec, with its aggressive bumpers and chintzy wheels.

Audi claims this new A6 is the best one yet to drive, which worries us. With the A4 it famously decided against chasing BMW and Jaguar and concentrated on making the car quiet, comfortable and refined instead of thrilling. The result is perhaps the best A4 ever. We wish it had gone down the same route with the A6, which is neither as comfortable nor as fun as the 5 Series (whose breadth of ability is as impressive now as it was the day it was released. Very). The Audi’s S Line suspension is overly firm, the steering numb and chassis uninvolving. Four-wheel steering and adaptive dampers can be optioned in and do improve things, but our test car had neither.

As for engines, there’s not much in it between the two 2.0-litre turbodiesels. Four-cylinder diesel engines are inherently unrefined, but these two are as good as you’ll find anywhere. Both are paired with automatic gearboxes – a dual-clutch seven-speed in the Audi and a more conventional eight-speed automatic in the BMW – that make the best of their engines’ narrow power bands. Again, it’s the BMW that edges ahead here – its gearbox is smoother and more decisive than the Audi’s, which can suffer from a bit of unwelcome lag, especially when you’re trying to make a fast getaway at a roundabout or junction.

At least both cars feel well-made. Their interiors match almost button-for-button the interiors of their manufacturers’ luxury cars – the 7 Series and A8, but look closely and you’ll see the cost-savings. More plastic, less metal and leather – but neither feels in the least bit cheap as a consequence. As for space, the boots are identical, and rear-seats more than big enough. Where they differ is in operating concepts.

Audi’s infotainment system eschews conventional switchgear in favour of two touchscreens. The top one does navigation, media, phone and so on, while the smaller one beneath is reserved for the climate controls. Even though both give haptic feedback and have smart, logical menus and high-resolution displays, neither is especially easy to use while driving. Good thing, then, all the important functions can be accessed via the ‘Virtual Cockpit’ instrument cluster, which is operated via buttons on the steering wheel.

Meanwhile in the 5 Series, the central display sits on top of the dashboard and can be operated either via touch or a rotary controller down by the gearlever. The climate controls are button-operated, as indeed they have been for decades. iDrive has been refined over the years, getting steadily more user-friendly, but the number of features and options it now offers is baffling. There are digital dials here too, but they do little besides replicate actual dials. Which rather defeats the point.

So when it comes to interiors, practicality and so on, it’s more or less a dead heat between these two. Driving, however, is a different story. Despite Audi’s best efforts, the A6’s overly firm ride and uninvolving chassis mean it’s neither as much fun, nor as comfortable as the 5 Series, regardless of its well-appointed cabin. So what we’d do is, erm, buy a Volvo S90. You’re welcome.