Parkers overall rating: 4 out of 5 4.0

Miles per pound (mpp) Miles per pound (mpp)

Petrol engines 4.7 - 7.7 mpp
Diesel engines 7.0 - 10.2 mpp
Low figures relate to the least economical version; high to the most economical. Based on WLTP combined fuel economy for versions of this car made since September 2017 only, and typical current fuel or electricity costs.

Fuel economy

Petrol engines 22.1 - 36.2 mpg
Diesel engines 34.9 - 50.4 mpg
  • Diesels are punchy yet economical
  • 40 TDI is the most efficient
  • Servicing could prove pricey 

Despite its powerful engines, the A6 Avant’s fuel consumption figures are rather impressive, but can vary depending on the wheels fitted. Those with larger alloy wheels tend to have slightly higher fuel consumption.

The 40 TDI claims between 57.6 and 60.1mpg on the combined cycle. Sport models with standard 18-inch wheels claim the highest economy figures.

For the 50 TDI, claimed fuel economy of between 47.9 and 48.7mpg is achievable if you don’t have too much of a heavy right foot, making the 40 TDI the go-to option for fleet users and those wanting the cheapest fuel costs. 

That figure isn’t far off the promised 42.2–42.8mpg from the petrol-powered 45 TFSI, while the thirstiest A6 Avant is the 55 TFSI with 39.2mpg.

The highest performance variant, the S6 Avant, claims 35.3mpg is possible.

Like the fuel economy figures, the amount of CO2 emitted by A6 Avant models depends on the wheel size.

The 40 TDI emits between 124 and 129g/km of CO2, with Sport models with smaller wheels boasting the lower figure.

The 50 TDI produces between 151 and 155g/km, again variable based on the size of the wheels.

Features such as stop-start with mild hybrid technology allow the A6 to be more eco-friendly, cutting the engine earlier with the help of coasting functions and faster-starting in stop-start traffic. 

As you’d expect the TFSI line-up is more polluting in terms of CO2, with 153–151 g/km from the 2.0-litre 45 TFSI and 164–163 g/km from the most powerful 55 TFSI. Both less than the S6 however, which produces 171g/km of CO2.

Reliability

  • The A6 Avant looks and feels solidly built
  • Lots of new electronic systems fitted
  • Some new mechanical parts too 

While the A6 Avant looks and feels every inch the premium product, that doesn’t always mean it’s going to be trouble-free.

The interior is made from solid and plush materials and we imagine it would take a long time for any squeaks and rattles to make themselves known, but it’s possible there could be some niggles over time.

For example, there have been issues with existing systems of Audi’s Virtual Cockpit digital dials. We’re hoping the updated system in the A6 remedies these, but it’s worth keeping an eye out.

Similarly, we’ve experienced one or two issues with the Matrix LED headlamp units malfunctioning on other models and could be expensive to fix. Luckily, it’ll be a little while yet before the A6 is out of warranty, so you should be covered.

The A6 also uses new technology from the A8, but this has proven dependable so far, and if any issue arise with the MMI Touch system, it’s likely a software tweak will be the solution.

Everywhere else, the A6 makes use of familiar Audi parts, with proven engines and gearboxes that shouldn’t be problematic. 

Ongoing running costs

Road tax (12 months) £475
Insurance group 30 - 50
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