Audi Q8 - MPG, CO2 and running costs

​The two engine options in the standard Audi Q8 line-up give buyers the choice of petrol or diesel power – the latter with mild-hybrid electric assistance. As you’d expect the 50 TDI diesel is markedly more efficient, offering a best of 34.9mpg on the WLTP combined cycle with CO2 emissions of 213g/km.

The petrol powered 55 TFSI will be quicker but it’s also a fair bit thirstier, coming in at 27.2mpg. It’s also more polluting at a rate of 253g/km of CO2. As prices start from around £73,500, all versions of the Q8 cost £570 a year in VED road tax for years two to six of ownership. You won’t get off lightly on Benefit-in-Kind tax if you’re a company perk driver either – the Q8 is in the highest percentage tax bracket whether you choose petrol or diesel power.

Unsurprisingly, neither the SQ8 nor RS Q8 are exactly eco-friendly performers, with official economy and CO2-emission figures of 23mpg and 289g/km, and 21.2mpg and 307g/km, respectively.

Mild-hybrid tech comes as standard in the diesel-powered Q8. There’s a lithium-ion battery under the boot floor, which is regenerated under braking. When coasting between 34mph and 99mph, the diesel engine’s stop-start tech cuts fuel and progress is maintained using the belt drive starter motor.

Insurance groups

The high price and strong performance of the Audi Q8 ensures high insurance premiums, too. The entire lineup, including the SQ8 and RS Q8, sits in insurance group 50. Although it is very closely related, the Audi Q7 sits as low as group 44 in entry-level S-Line spec. 

Depreciation

Our expert data suggests that the lower-spec Q8s should fare reasonably well after three years and 36,000 miles, retaining around 50 per cent of their initial value. The range-topping Vorsprung performs worse, though, returning around 42-46 per cent. It’s important to remember that all Q8s have a high list price, so it could still cost quite a lot when the time comes to sell yours on.