• Plug-in hybrid most economical on paper
• All models have low motorway MPG
• Diesel still the best all-rounder

What are the running costs?

If you’re looking for the best fuel economy, the 50 TFSIe plug-in hybrid is the way to go. However, bear in mind that it works best on shorter journeys and with the battery topped up. Used in that way, it’s easy to achieve more than 60mpg. Longer motorway runs will see it drop to 35mpg, while running it in EV mode will get you around 30 miles. As PHEVs go, it’s one of the best.

Opt for the 40 TDI diesel and fuel economy improves in real world driving to between 45-50mpg, especially if you’re one for longer motorway trips. Moving up to the most powerful diesel, the S6, will bring about a penalty in running costs, but fuel consumption is still better than 35mpg in most driving conditions, which is excellent considering its performance.

Finally, the 40 and 45TFSI petrols prove to be surprisingly effective at sipping fuel on motorway runs. The least powerful petrol has a range should return 33-37mpg, while the 45TFSI will achieve about the same, which seems like good value to us.

38

Servicing and maintenance

You’ll find the Audi’s servicing and maintenance costs are about the same as BMW and Mercedes-Benz – in other words, fairly expensive, but with high levels of customer satisfaction from its dealers.

Audi’s standard warranty, at three years or 60,000 miles is falling behind the more mainstream brands, and smacks a little of complacency. When you consider that BMW’s warranty, which is three years and unlimited mileage, this is disappointing. But you can extend the warranty to four years/75,000 miles or five years/90,000 miles for extra money.

But considering you can buy a Kia or an MG with seven year’s support, and Toyota will cover its cars (when serviced in dealer) for 10, Audi needs to up its game.

Reliability

• The A6 Avant is solidly built 
• But reliability for the model is only average 
• Lots of technology to go wrong

There’s a huge amount of tech to go wrong here, and for example our testers have experienced issues with the Virtual Cockpit and Matrix LED headlights on other models. Audi’s scores in JD Power customer satisfaction surveys is not great, while Parkers users report many niggling issues in owner reviews.

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.