Used Audi A6 review

A full used buyer’s guide on the Audi A6 covering the A6 Mk3 (2004-2011) and the A6 Mk4 (2011-date)

While the compact executive sector tends to dominate column inches and new car sales, move up a class to an executive model and things get even more enticing. Take the Audi A6, for example. Compared with its smaller A4 stablemate, it has more space, more equipment and more comfort – and when buying new, it also costs more.

However, on the used market, such large models can represent spectacular bargains, as they tend to depreciate at a faster rate. This means you get a huge amount of car for your money. That’s certainly the case with the A6, which offers fast and frugal motoring with refinement and comfort thrown in.

Models covered 

The Audi A6 has a come a long since first appearing in 1994. The executive car is now in its fourth generation and we’re looking at both this latest model, which has been on the market since 2011, and its Mk3 predecessor. 

  • Audi A6 Mk3 (2004-2011) - You get a lot of car for your cash with the Audi A6. Are there any pitfalls?
  • Audi A6 Mk4 (2011-date) - Premium executive car is now tremendous value second-hand

Audi A6 Mk4

Prices from £12,000


The A6 Mk4 saloon launched in March 2011, with 175bhp 2.0 or 242bhp 3.0 TDI diesels or a 3.0 TFSI petrol. In November, the A6 Avant (estate) arrived with the same engine and transmission options, along with a 310bhp 3.0 TDI. In 2012, the 3.0-litre-only A6 Allroad estate appeared, along with the 415bhp V8-powered S6. October 2013 saw a 201bhp 3.0 TDI quattro join the range, four months before the frugal 187bhp 2.0 TDI Ultra superseded the regular (175bhp) 2.0 TDI.

A facelift in November 2014 brought tweaked styling, lighting upgrades, more efficient engines and a revised multimedia system. Further multimedia updates and extra standard equipment are planned for July 2016.

Audi A6 Mk4 reviews

Audi A6 in-depth reviewAudi A6 Ultra in-depth reviewAudi A6 Avant in-depth reviewAudi A6 Allroad in-depth reviewAudi A6 2.0 TDI reviewAudi A6 2.0 TDI Ultra reviewAudi A6 3.0 TDI S-Line reviewAudi A6 3.0 BiTDI S-Line reviewAudi A6 Black Edition reviewAudi A6 Hybrid reviewAudi A6 Avant 3.0 TDI reviewAudi A6 Avant 3.0 BiTDI reviewAudi A6 Allroad 3.0 BiTDI review

Which one should I buy?

All of the engines and gearboxes are excellent, but petrols are very rare, so it’s more likely you’ll buy a diesel in either 2.0 or 3.0 form. While the latter is smooth and very muscular, the 2.0 TDI is all you need.

The two key trim levels are SE and S line, although a Black edition was introduced at the end of 2012. The SE comes with bi-xenon headlights, a 6.5-inch colour display, DAB radio, 10-speaker hi-fi, power-assisted tailgate (Avant only), four-zone climate control, leather trim, cruise control plus auto lights and wipers. S line adds 18-inch alloys, LED headlamps, sports seats and a multifunction steering wheel. The Black also has privacy glass, 20-inch wheels, a styling kit and a Bose surround-sound hi-fi. 

Alternatives to the Audi A6 Mk4

The BMW 5 Series is the best driver’s car in the sector, with superb engines and boxes, great steering and fabulous quality. Offered in saloon or estate (Touring) forms, it tends to be priced a little higher than the Audi.

Also a bit more costly is the Mercedes E-Class, which also has excellent engines and transmissions. The hi-tech Mercedes is spacious and comfortable, and comes in saloon, coupe, estate or convertible forms.

The Jaguar XF is available in saloon and estate forms and is stylish, well made and affordable, while the interior is beautifully designed, if now a bit dated. Further alternatives include the Skoda Superb and Lexus GS, both of which always do well in our annual Driver Power survey.

What to look for:

Parking brake 

A software upgrade can be required in order to fix a fault with the electronic parking brake refusing to release.

Fuel gauge

Gauges can read empty even when the fuel tank is full; Audi is aware of this, and the problem is usually fixed with another software upgrade. 

Oil levels

The TDI engines can commonly use around a litre of oil every 1,000 miles, so check the powerplant isn’t running on empty.


Rear light cluster seals can sometimes fail, allowing water to get into the lenses. The cure is to fit both new lenses and seals. 


The design might be staid, but the build quality is superb and there's space for five - although the transmission tunnel restricts legroom for the middle passenger.


Boot space is excellent, at 530 litres, or 995 litres with the seats folded. The Avant is even better, with up to 1,680 litres available.

Running costs

All A6s come with variable maintenance, so the car flags up when a service is due and takes a multitude of factors into account. The longest an A6 can go between services is two years or 19,000 miles, alternating between minor and major attention. For 2.0-litre cars, these are priced at £159 and £309 respectively, while you’ll pay £199 or £399 if you buy an A6 with a 3.0-litre TDI engine.

Only the 2.0-litre TDI features a cambelt, which has to be replaced every five years or 140,000 miles, at a cost of £455. The 3.0 TDI powerplant is chain-driven, so doesn’t need attention. The brake fluid has to be replaced after three years, then every two years, at £59; an air-conditioning service is priced at £79.


The A6 has had three recalls, the first of which was in October 2014. Some 2012-2014 cars could lose brake power assistance, yet the stoppers would still work. The next recall was due to fuel leaks in the 3.0 TFSI.

Most recently, the diesel emissions scandal affected some 2.0 TDI cars, but no 3.0 TDIs. There’s no safety issue and should be no financial implications, either, for economy or road tax increases. Check your potential buy at

Driver Power owner satisfaction

The A6 Mk4 debuted at 27th in our Driver Power 2013 satisfaction survey, rose to 26th in 2014, slipped to 54th last year and most recently ranked 81st. Build quality (24th), practicality (45th) and seat comfort/in-car tech (both 56th) were its 2016 highlights. But 131st for reliability and 117th for running costs disappoint.


If you’re looking for an ideal family carry-all, the A6 should fit the bill perfectly. When it arrived in 2011, it was crowned Best Executive Car in our annual New Car Awards – a feat that it repeated in 2014, despite some very stiff competition.

The big Audi is relatively pricey when new, but depreciation makes it more affordable than you might think used; a three-year-old 2.0 TDI SE saloon with 35,000 miles can be yours for a mere £15,000. That’s less than half what it cost new, yet at this mileage it’ll be barely run in. However, while the A6 is hugely appealing, reliability can be an issue, so check any potential buy very carefully. 

Click through to page two for our full buyer's guide on the Audi A6 Mk3 sold from 2004 to 2011... 

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