The Audi A6 is far from a head-turning car, but it remains one of the top business cars in its segment, on a par with rival German stablemates, the BMW 5 Series and Mercedes E Class. Exciting it is not, but with such a strong brand image and such understated style, the A6 saloon certainly has its place in the carmaker’s line-up.We’ve tested the most powerful and the most expensive A6 saloon – the rather fun 3.0-litre V6 quattro model. Performance 5/5 Thanks to twin turbochargers and the meaty 3.0-litre V6 diesel with 309bhp, this tame-looking car achieves 0-62mph in a surprising and rapid 5.1 seconds. That’s only half a second slower than its performance sibling, the S6. The competing BMW 5 Series 535d is on a par at 5.3 seconds, but the Mercedes E Class 350 BlueTEC AMG is notably slower at 6.6 seconds. There’s a huge 650Nm of torque and gearshifts are effortless – this iteration is the only one in the range to feature the eight-speed automatic tiptronic gearbox, which changes up and down with ease, aside from the slightly slow reaction at the offset, common in diesel automatic cars. The car is happy in town, but really comes into its own for long-distance cruising, the acceleration creates a joyous warble, while excellent brakes only add to the sportscar feel. And there’s a pleasure found in having this sort of performance, mixed with the sedate looks of an A6. It’s a real sleeper – you’d expect a perfectly satisfactory 2.0-litre TDI in this shell, but instead, you find a speedy motor that could race the best of them. Ride and handling 4/5 Audi is typically good at ride and handling and this is no exception, no doubt helped by the car’s four-wheel-drive system. And there’s almost zero body roll and balanced weighting. Still, there’s the familiar four-ringed trait of artificial steering, which irritates more hardcore motorists, but, realistically, will go unnoticed by the average Audi driver. The car also features Audi’s Drive Select which can be left in Auto mode. The Comfort setting is likely to be popular in this type of big practical family car, but considering the performance element, Dynamic mode certainly has its place too, giving more reactive steering, throttle response and thrilling traction out of bends. Equipment 3.5/5 The mid-range SE trim that we tested is decently specced, with 17-inch alloys, leather seats, rear parking sensors and cruise control. There’s also automatic lights and wipers, hill-hold assist and the brand’s intuitive infotainment system, MMI Plus, which includes a 6.5-inch retractable colour screen and DAB radio. Our car also had some pricey options including £300 heated front seats and a £1000 BOSE surround sound system. The boot is cavernous at 530 litres – the 5 Series has 10 litres less and the E Class, 10 litres more. Running costs 3.5/5 It’s not bad on the efficiency front, all things considered. Official combined figures for efficiency are 44.1mpg – our test car was averaging 35.1mpg on a lot of motorway driving, and a little lower-speed stuff too. Emissions are 169g/km CO2. However, it’s lagging behind the competition – the equivalent 5 Series does 52.3mpg and emits 143g/km and the E Class offers 47.9mpg and 154g/km. Verdict 4/5 For the average business driver, this £44,670 model will be hard to justify. But for some top executives, this brilliant, heady mix of performance and a large, practical car will be the perfect companion. In all honesty, there’s not much in it between the A6 and its rivals. The E Class is cheaper and the 5 Series is more expensive. They’re both more efficient and economical than the A6, but then they’re slower too. Ultimately, buyers of these cars are likely to base their final decision on styling and brand preference, but this A6 remains in the top picks.