• PHEV is the best performer here
• Diesel for long distance
• Avoid the S8 if fuel costs are an issue

What are the running costs?

With list prices easily broaching six figures, A8 running costs are not exactly priority number one, but for those companies that run these cars on their fleet, it’s reassuring to note that they will be less expensive to run than the model they replaced. Going on the figures alone, the plug-in hybrid version is the one to have.

According to official figures, both the standard- and long-wheelbase models will get close to 100mpg thanks to a near 30 mile electric-only range. Ensure you hardly (if ever) use the petrol engine and obviously the fuel cost figure will be much lower.

The A8 is a big and powerful car, so don’t expect to get close to that 100mpg figure if you regularly use the petrol engine. The diesel engine also proved to be a mixed bag. Audi reckons it can achieve 39.8mpg, a figure we beat on a long run. However, around town we saw it dip to below 20mpg, which is sub optimal.

All normal A8s benefit from electrification (although only in the form of mild hybridisation) which means there’s some battery assistance, but won’t run solely on it alone like the PHEV does. As a result both V6s have low-ish CO2 emissions , so they’re a step in the right direction.

View full Audi A8 and S8 specs

Servicing and warranty

There should be no unpleasant surprises when it comes to servicing and maintaining an A8, as it is a luxury product offered by a premium carmaker – it’s going to be expensive, and rightly so. A number of service packages are also available from main dealers.

Warranty is three years and 60,000 miles, which you can extend to four or five years at an additional cost. Compared with up-to 10 years offered by rivals, Audi’s warranty looks unimpressive.

Reliability

• Lots of tech and driver assistance systems
• It’s all used elsewhere though, same for the engines
• Owners’ reviews report good things about reliability

As a big and technologically advanced car there are a number of areas where the Audi A8 could prove unreliable but we don’t think you should have too much to worry about in this regard.

The engines and MMI infotainment screens are used elsewhere, and the A8 has been assembled with a high standard of quality and solidness.

Also unlike a lot of smaller Audis, which can be plagued with reliability issues as they fall into middle age, Audi A8 owners report few issues and seem a happy bunch.

• Check out Parkers owners reviews of the Audi A8 (2010-2018)

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