To paraphrase Henry Ford, you can have any Audi A6 saloon of 2011-18 you like, so long as it’s diesel. In fact, make that a 2.0-litre diesel, or 2.0 TDI as Audi has it. We exaggerate, of course, but only a little. The fact is that A6 2.0 TDIs outnumber any other A6 saloon variants of the same generation by a huge margin.
It’s not surprising, given the A6’s target market and the company car tax structure when it was new. Then there’s the engine itself, which bows only to the BMW 520d in terms of civility. The 2.0 TDI Ultra, launched in 2014, is extremely economical, too.
This emphasis on diesel could seem less of a draw for used car buyers, whose mileage might not appear to justify choosing an oil-burner and for whom benefit-in-kind tax savings are irrelevant. However, for these people, there are still good reasons to choose an A6 2.0 TDI or its siblings, the 3.0 TDI and high-performance 3.0 BiTDI. They include the sheer pleasure to be gained from driving such a comfortable, well-appointed and well-engineered car that is also economical and inexpensive to tax. Perhaps of greater appeal, though, is that most A6s are attractively priced, not least because buyers are favouring SUVs over executive saloons.
How about £13,500 for a 2016- reg 2.0 Ultra SE Executive S tronic with 33,000 miles? And road tax is just £30. You want something meatier? A 2016-reg 3.0 TDI quattro SE Executive S tronic with 28,000 miles is £15,995, or a same-age and mileage 3.0 BiTDI quattro SE Tiptronic (its V6 produces 316bhp and 479lb ft of torque) is £19,995. These 3.0-litre engines are seriously muscular but the 2.0 TDIs are also powerful and serve most drivers perfectly well.
Those are the diesels, but if you hanker after a petrol, and have the patience to scour the classifieds for one, you’ll be rewarded by a choice of 2.0 and 3.0 TFSI engines (there’s a 2.0 TFSI hybrid but it’s as rare as hen’s teeth) and, later in the model’s life, a 1.8 TFSI. Prices start from £13,000 for a 2011-reg 3.0 TFSI quattro SE S tronic with 37,000 miles. Which just leaves the potent S6, a model that deserves its own guide and costs from £20,000 for a 2013-reg with 44,000 miles.
This fourth-generation A6 was facelifted in 2014, when it gained styling tweaks, upgraded infotainment and more efficient engines. A second refresh came in 2016 (additional equipment and technology, redesigned front air intakes and a restyled rear end).
Throughout, the core trims remained SE and S line, with the fully loaded Black Edition arriving in late 2012. SE is the most comfortable thanks to its smaller alloy wheels and steel springs. If your budget will allow, go for the post-2016-facelift SE with additional equipment.
Engine The 2.0 TDI has a cambelt that must be changed every five years or 140,000 miles. Early 3.0 TDIs can suffer timing chain noise cured by the fitment of updated chain sensors. The diesel engines get through oil, so check the level on the dipstick. Check the ash loading report on the diesel particulate filter and arrange an extended loan (overnight loan if possible) to see if it goes into DPF regen mode. Some Ultra diesels have had problems with their AdBlue sensors and fuel pumps. Because they're direct injection, the petrol engines need regular oil changes and premium-grade fuel. Issues can include oil and coolant leaks and worn turbos. Audi says 1250 miles from a litre of oil is normal on the 2.0 TFSI.
Transmission Owners report issues with the Multitronic and occasionally with the S tronic automatic gearboxes, so check changes are smooth and quiet. An S tronic should have had fresh fluid and filters every 38,000 miles.
Suspension Listen for creaking noises from cars fitted with air suspension (likely to be the control arm inner bushings).
Brakes Be sure the automatic handbrake operates correctly. A software update should cure any problems.
Interior Be sure the fuel level display is accurate. Again, a software update should restore it to health. If the car has a panoramic sunroof be sure it seals and operates properly. Check the infotainment screen rises on start-up.
Need to know
In the latest What Car? Reliability Survey, the A6 ranks fourth in its class, just ahead of the Mercedes E-Class, BMW 5 Series and Jag XF.
Condition-based servicing means A6s may have gone for up to 19,000 miles without an oil change – good for fleet managers’ bottom lines but not necessarily engines’ bottom ends.
Larger wheels on S line trim upwards spoil the ride.
Revised cars from September 2014 have Euro 6-compliant engines. Check the V5 document for confirmation.
Audi A6 2.0 TDI SE Executive Ultra: This entry-level model avoids the S line’s stiffer ride but still spoils you with front and rear parking sensors, four-zone climate control, leather seats, a multimedia interface and a digital radio.
Audi S6: Its 4.0-litre V8 should be ample justification but there are some pretty wild features too, among them active noise cancellation, a quattro drivetrain with a sports diff and figure-hugging sports seats.
Ones we found
2013 2.0 TDI S line, 159,000 miles, £5995
2015 2.0 TDI Ultra SE, 80,000 miles, £10,495
2017 2.0 TDI Ultra SE Executive, 28,000 miles, £15,000
2019 2.0 1.8 TFSI S line S tronic, 13,000 miles, £20,750