• PHEV is most economical
• All claim to reach 40mpg (ish), but some seem ambitious
• Diesel best all-rounder

What are the running costs?

Economy champion is the plug-in hybrid. Officially it’s capable of 235.4-256.8mpg, but these figures are fairly unrepresentative. If you make lots of short journeys and keep the battery topped up, mpg in three figures might be achievable. On an 85 mile trip with half a battery we averaged about 60mpg. Audi reckons it can travel 30 miles on pure electric power but we reckon it’s closer to 25.

Opt for the 40TDI engine and fuel economy will range between 47.1-50.4mpg according to Audi. Moving up to the most powerful diesel, the S6, will bring about a penalty in running costs but it’s less than you might think – Audi says 40.4mpg is possible, despite the huge performance available on tap.

The least powerful petrol has a range of between 37.2-39.8, while the 45TFSI seems like good value considering the extra performance it has. Officially it’ll do 34.9-37.2mpg.

We do know that the A6 has particularly strong resale values, though, particularly if you go for one of the more popular engine and trim combinations.

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Servicing and maintenance

You’ll find Audi’s servicing and maintenance costs on par with BMW and Mercedes-Benz – in other words, fairly expensive, but with high levels of customer satisfaction.

Audi’s standard warranty, at three years or 60,000 miles is stingy compared with others. Especially BMW’s, which is three years and unlimited mileage. But you can extend the warranty to four years/75,000 miles or five years/90,000 miles for extra money.

Reliability

• Certainly looks and feels solidly built 
• Previous models have fared well 
• Lots of new technology

There’s a fantastic amount of tech to go wrong, and for example our testers have experienced issues with the Virtual Cockpit and Matrix LED headlights on other models.

The A6 has been recalled a couple of times so far, with issues around a towing bracket (where fitted) and the rear window. If you’re looking for a used A6 then a dealer will be able to confirm whether or not the work has been undertaken.