Audi A8 saloon (2010-2017) - MPG, running costs & CO2

The Audi A8 is surprisingly economical for a car of this size, but it'll still be expensive to run

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The A8 is Audi’s flagship saloon and it’s not cheap to buy or run relative to other cars on the road. Given the car’s size, speed and luxury, however, it’s reasonably efficient with a diesel engine. Insuring the car is likely to be expensive, though, as is replacing consumables such as tyres and brakes.

Audi A8 MPG & CO2

The most economical A8 is the 3.0-litre TDI diesel, which returns 49.6mpg and has CO2 emissions of 149g/km. Bear in mind that these figures relate to the car with 18-inch alloy wheels; bigger rims produce more CO2 and bump up the fuel consumption figure by up to 2.5mpg. The more powerful 4.2-litre TDI diesel manages 39.2mpg economy and CO2 emissions of 189g/km with 18-inch wheels.

The sole petrol-powered short-wheelbase A8 is the sporty S8. It has a 513bhp 4.0-litre turbocharged engine that’s powerful but not very economical. It’ll do 30.1mpg and has CO2 emissions of 216g/km. The more powerful 597bhp S8 Plus returns 28.2mpg and CO2 emissions of 231g/km. 

The only other petrol model is the huge 6.3-litre W12 long-wheelbase car. Unsurprisingly, it’s not at all cheap to run. Go for this model and you’ll see just 25.7mpg economy and CO2 emissions of 254g/km putting it in the top 37% BiK band.

The long-wheelbase version is available with the same diesel engines as the standard A8, but its efficiency figures are fractionally worse due to the car’s slightly higher weight.

Every version of the A8 costs more than £40,000, so you’ll need to spend £450 a year on road tax for the first five years of ownership, regardless of which engine you choose. If you're choosing a company car, you’ll almost certainly want the 3.0-litre diesel, thanks to it being in the 29% Benefit-in-Kind (BiK) band, compared to 37% for the S8.

Insurance groups

The A8 is an expensive car and all models in the range are capable performers, so insurance won't be cheap. The entry-level diesel is in groups 47 to 48, while the S8 is in group 49 and the S8 Plus, 4.2-litre TDI and W12 are all group 50 – the most expensive category.


Audi offers a fixed-price service plan that covers the A8 for three years or 60,000 miles, whichever comes first. The plan includes all scheduled servicing, costs £350 and is available for all models apart from the W12. Considering the size and complexity of the A8, this seems very reasonable.


All A8 models come with a three-year warranty that runs to unlimited mileage in the first two years of ownership and up to 60,000 miles in the third year. The warranty can be extended to four years or 75,000 miles for £1,035, and five years or 90,000 miles for £2,555.

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