Audi Q8 review - MPG, running costs & CO2

Recent large Audis have demonstrated considerable innovation in fuel-saving technology. Like the A8 saloon, the Q8 is built around a 48v power system, which facilitates mild-hybrid technology, as well as performance-boosting measures such as electric turbocharging. Be under no illusion that the Q8 will be inexpensive to run, though. This is a big, heavy car with a considerable appetite for fuel; maintenance won't be cheap, either.

Audi Q8 MPG & CO2

Claimed fuel-economy figures for the Q8 are not too dissimilar to those of the Audi Q7.

The 3.0-litre 50 TDI Quattro with mild-hybrid technology claims up to 34.9mpg and produces from 212g/km of CO2 depending on the size of the alloy wheels.

A 3.0-litre petrol 55 TFSI model is the only petrol model in the mainstream Q8 line-up; it’s less economical than the diesel, as you’d expect, managing up to 27.4mpg and CO2 emissions from 235g/km. Company-car users will have to pay the top rate of Benefit-in-Kind (BiK) tax on any model in the Q8 range with the exception of the Q8 55 TFSI e plug-in hybrid.

The plug-in hybrid 55 TFSI e costs around £8k more than the petrol and diesel engines, but will bring big BiK savings thanks to its 30-35g/km CO2 output. If you use it as intended and recharge the battery regularly, you could achieve up to 217mpg and up to 50 miles of fully electric driving. This was a big increase from the pre-facelift version, which could only get around 28 miles with zero tailpipe emissions.

The Q8 PHEV offers a choice of driving modes, with one letting you save the battery power for later in the journey. While the BMW X5 xDrive45e used to offer a longer electric range and better efficiency as a result, the pair are now much more evenly matched.

With every Q8 priced comfortably beyond the £40,000 mark, annual road tax will cost more than £500 at the end of each of the first five years of ownership, and the rate for hybrids per year thereafter as mild-hybrids also qualify for the slightly reduced tax rate.

Insurance

The S line 3.0-litre diesel starts in group 47. The higher-spec Vorsprung and more powerful 55 TFSI petrol are both insurance group 49. As you’d expect, the SQ8, which we’ve reviewed separately, is rated in the highest insurance group 50.

Servicing

The Audi Q8 requires servicing based on either an annual or variable schedule, which you can determine when you take delivery. Annual is intended for low-mileage drivers and those who make frequent short journeys. If you spend a lot of time on the road, a variable schedule might suit – it uses wear sensors and oil-quality evaluation to determine when a service is required, but no longer than two years will ever elapse between services. Audi offers service packages to suit drivers' individual requirements; your dealer will be happy to discuss the most suitable arrangement for you.

Warranty

Audi's three-year/60,000-mile warranty is less generous than the three-year/unlimited-mileage policies offered by Mercedes and BMW, but can be extended at extra cost. Nevertheless, it still galls that a premium brand with a reputation for quality should offer such a mean warranty, when Toyota, Nissan and Hyundai offer five or more years, with a far more generous mileage limit.