Audi A6 Review (2011-2018)
Audi A6 Saloon cars for sale
4.0
Expert review
Pros
Stylish and comfortable interior
Relaxing to drive, especially over long distances
A wide choice of engines to suit different budgets and needs
Cons
Not as much fun as a BMW 5 Series
S Line models have a less comfy ride
Some reliability woes with the automatic gearboxes

The CarGurus verdict
As either a saloon or estate, the Audi A6 is classy and eye-catching, and its interior decor is about as stylish as you can get without buying a Bentley. Its standard equipment levels were pretty generous when the A6 was new – leather upholstery, air con, satnav and much, much more are common to all – and chances are that the original owner ticked some tasty options too: just make sure it all works.
Comfortable and effortlessly fast, this executive Audi is more entertaining to drive than previous models. Admittedly, it's still not as well suited to keen drivers as a BMW 5 Series, but for many of the people who are considering buying this kind of car that simply won't be a priority.

What is the Audi A6?
The fourth-generation Audi A6 was sold between 2011 and 2018, and can make for a fantastic used buy. It's a refined and sophisticated executive car with lots of space inside, smooth driving manners and a first-rate interior. With good insulation from wind-, road- and engine noise, it's also an excellent car for covering long distances.
The Mk4 Audi A6 sold in reasonably large numbers during its seven-year lifespan, so you should be spoilt for choice when it comes to finding one with the right engine, specification and even colour.

How practical is it?
Audi’s challenger to the BMW 5 Series and Mercedes-Benz E-class really raised its game in a variety of areas as it evolved into this fourth generation in 2011, and practicality is one of those areas. The 530-litre boot of the Audi A6 saloon is very large and well shaped, and can be expanded by folding down the 60:40 split rear seats. The Avant estate model is even more capacious, with 565 litres of space beneath the load cover.
Inside, meanwhile, there’s a generous amount of space in the rear for two passengers, though the picture’s not so rosy for a third sitting in the middle: not only does the transmission tunnel rob them of foot space, the centre console between the front seats intrudes on their knee room.
What's it like to drive?
It’s easy to be seduced by the S Line models’ sporty appearance, but their larger (18in) alloys and lower, stiffer suspension make for choppier ride quality than you get with the SE Executive version.
Having said that, every A6 is smooth and suave to smear along in, making mincemeat of long motorway journeys with very little in the way of engine-, wind- or road noise.
The trade-off for this is that it isn’t quite as much fun to drive as the BMW 5 Series, and nor does it feel quite as assured in corners as the Mercedes E-Class. But if you don’t plan on chucking your big executive saloon around (and let’s face it, few people do), you probably won’t mind or care.
For more info on the engines available in the Mk4 Audi A6, see the 'Three things to know' section of this review.

Technology, equipment & infotainment
SE might be the entry-level model, but the equipment list isn’t exactly stark; there’s cruise control, automatic lights and wipers, front- and rear parking sensors, keyless starting, satellite navigation, and Bluetooth connectivity, all of which come as standard.
Upgrading to an S-Line brings you those larger alloy wheels and that stiffer suspension, although you also get sportier styling, Xenon headlamps, LED rear lights, and electric seat adjustment.
Audi’s MMI infotainment system can be a little fiddly to use in places, but for the most part, the joystick in the centre of the car makes it easy to control on the move. The rest of the A6’s cockpit is a paragon of quality, with handsome styling and upmarket materials throughout.

Audi A6 running costs
Although you might want to knock 10-15mpg off Audi’s claimed fuel consumption figures to give you a better idea of real-world economy, most A6s treat you fairly kindly at the pumps. The 2.0 TDI Ultra diesel is the star of the range, and when teamed with the S tronic automatic gearbox, is reckoned to be good for 67.3mpg. The regular 2.0 TDI posts figures in the mid-50s, as do the 3.0 TDI models, although some versions of the latter will do 64mpg. One reason for the unpopularity of the 3.0 TFSI petrol engine is its 34mpg fuel consumption; the run-out 1.8 and 2.0 TFSI range between 42 and 49mpg.
Audi has fixed-price servicing packages for the A6 that operate on the basis of annual visits to the dealer, or every 10,000 miles, whichever comes around sooner. A minor service costs around £160-200 depending on the model, and a major one £320-400. Original owners might have been running their car to a variable servicing schedule, with a maximum of two years or 19,000 miles between workshop visits, but with secondhand A6s, you might want to consider annual servicing to be on the safe side.
The 2.0 TDI diesel engine needs its cambelt replacing every five years or 140,000 miles, and that will set you back in the region of £450 at an Audi dealer. An air conditioning service is advisable every two years, as is a brake fluid change: budget for about £79 and £59, respectively.
The standard Audi warranty is three years/60,000 miles, both of which will have elapsed long ago. That' being the case, you might want to consider having it worked on by a good independent specialist to save money.

Audi A6 reliability
The mk4 Audi A6 has tended to do well in reliability surveys, but that isn’t to say that there haven’t been issues: you do need to be a little bit wary. Of greatest consequence is the fact there have been major faults reported with both types of automatic gearbox – the CVT-based Multitronic and the S tronic – on cars with more than 100,000 miles on the clock, involving complete failure. Given that a replacement costs a four-figure sum, either avoid high-mileage cars, or go for an extended test drive to ensure the automatic is working as it should in all conditions.
The diesel engines can have a considerable appetite for oil, in some instances consuming a litre of lubricant every 1,000 miles, so consult the dipstick to check that the owner of the car you’re considering has been keeping a check on consumption. And talking of consumption, some A6s have fuel gauges that read empty when they’re full: it’s a software glitch that should have been fixed by now, as should the one that caused the electric parking brake to fail to release.
Recalls for oil infiltrating the braking system and reducing braking performance, a possible fuel leak, and excessively high NOx emissions on some 2.0 TDIs should have been sorted by this stage, but remember to have that confirmed.
- Available as a saloon and Avant estate, the mk4 Audi A6 is powered predominantly by a range of turbodiesel engines: a popular 2.0-litre producing 175bhp and then 187bhp in its later super-efficient Ultra guise, and a collection of 3.0-litre V6 units with outputs spanning from 204bhp to the 315bhp pumped out by the gutsy 3.0 twin-turbo BiTDI. A turbocharged 3.0-litre petrol engine also graced the showrooms but sold in small numbers and was eventually discontinued: 1.8-litre and 2.0-litre TFSI petrol engines appeared for the final year of the mk4’s life.
- The only other petrol unit to make its way beneath the A6’s long bonnet is the 4.0-litre V8 bi-turbo found in the S6, RS6 and RS6 Performance, producing 444bhp, 552bhp and 596bhp respectively – though we’ll deal with these high-performance derivatives in more detail in a separate review.
- The A6 was unique in its class for offering front-wheel-drive models rather than rear-drive, although it can also be had with Audi’s quattro four-wheel drive system. A six-speed manual gearbox is standard: the automatic option for the 2.0-litre diesel and the lowest powered 3.0-litre is a Multitronic continuously variable transmission (CVT), with an eight-speed S tronic gearbox serving all the rest.
- Our favourite model: The 2.0-litre diesel Ultra engine with SE or SE Executive trim and Tiptronic automatic transmission. It gives 67.3mpg, produces just 109g/km of CO2, and pre-April 2017 models pay just £20-30 annual road tax depending on what alloy wheels they’re on.
- If you enjoy your performance: Any model with the 3.0 BiTDI twin-turbo diesel engine: it can zip from standstill to 60mph in as little as 4.9sec and will whisk on to 155mph. It also comes with quattro four-wheel drive and an eight-speed S tronic automatic gearbox.
- If you live in the countryside: As an alternative to an SUV, the A6 is available in Allroad guise, providing extra ground clearance compared with the rest of the range, and four-wheel drive. It’s powered by a 3.0 TDI diesel engine.
- If you want all the gadgets: Be on the lookout for any model with the Technology Pack Advanced option. It cost £3,500 when new and includes a premium satnav, a 7.0-inch infotainment screen between the instrument dials, adaptive cruise control, side assist with blind-spot monitoring, and lane-keeping assist. Also keep an eye out for a car with the then-£1,000 audio upgrade that provides a 600W Bose system with 14 speakers.

