Audi Q8 review - MPG, CO2 and running costs

The two engine options currently available in the standard 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 33.2mpg on the combined economy cycle with CO2 emissions of 217g/km.

The petrol powered 55 TFSI will be quicker but it’s also a fair bit thirstier, coming in at 26.6mpg. It’s also more polluting with a 240g/km of CO2. As prices start from around £67,000, all versions of the Q8 cost £490 a year in 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 22.8mpg and 282g/km, and 21.2mpg and 301g/km, respectively.

The 48-volt electrics in the regular Q8 make the mild-hybrid tech possible in the diesel version. 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.

16

Insurance groups

The high price and strong performance of the Audi Q8 ensure high insurance premiums too. The 3.0 V6 diesel versions are rated at Group 47E, while the more rapid petrol TFSI comes in at Group 47E. These groups are a little higher than equivalent versions of the Audi Q7.  Both the SQ8 and RS Q8 sit at the top of the insurance ladder in Group 50.

Depreciation

You can spend over £100,000 on a top-spec Audi Q8 before you’ve even had a look at the options list, so even though depreciation as a percentage of purchase cost is reasonably competitive at 53 per cent for the S line model (Vorsprung versions are around 46 per cent, reflecting a list price nearly £20k higher), it’s still going to cost you a chunk of change when it comes to move the vehicle on. It seems likely the added economy of diesel versions ought to make a difference on the used market.