The diesel engines offer the lowest running costs, particularly the 1.9 TDI. However Audi servicing is expensive so it’s worth searching out a good independent specialist – there are plenty about.

The A6 scores fairly badly on the eco front. With an average of 214g/km CO2 across the model line-up, its emissions are a touch high for an executive saloon. However, it’s worth noting that the line up has a high number of diesel models, bringing the average down and giving buyers more choices of low-emission versions. Diesels typically produce less CO2 than petrol engines with similar power outputs.

The range is not particularly economical, averaging 35mpg.

Reliability in the A6 tends to be exemplary, with only occasional problems reported by owners since it was launched in 1997. Maintaining a full Audi service history will help this.