Parkers overall rating: 4.3 out of 5 4.3
  • Two diesels and two petrols on offer
  • SQ8 is diesel, RS Q8 petrol
  • All engines have mild-hybrid technology as standard

The 'regular' Audi Q8 is available with a 286hp 3.0-litre diesel engine named the 50 TDI, and a 3.0-litre TFSI petrol engine (55 TFSI).

Each engine comes with Audi’s mild-hybrid technology (MHEV), that uses a 48-volt subsystem to recover energy when the vehicle is decelerating. It allows the Q8 to ‘coast’ with the engine off between speeds of 34 and 99mph, saving fuel as it does so.

Audi Q8 diesel engine

The Q8’s 50 TDI diesel engine is shared with other models in the Audi range, including the A6, A7 and A8. Producing 286hp and 600Nm of torque, it’s capable of accelerating from 0-62mph in 6.3 seconds and onto a top speed of 144mph.

It’s important to note that on the international launch of the Q8, the car was driven at high altitude where the engine’s performance is restricted thanks to lower atmospheric pressure.

Nevertheless, the 3.0-litre diesel still felt smooth and punchy, despite the altitude (and the Q8’s hefty 2.1-tonne kerb weight). The 600Nm of torque meant that overtaking could be carried out in a brisk and safe manner, with little drama from the engine. 

Like almost all large diesel engines, the Q8 50 TDI does its best work in the mid-range. There’s still a reasonable amount of pulling power up until a few hundred rpm before the red line, yet taking the engine above 4,000rpm feels unnecessary.

Audi Q8 petrol engine

The petrol engine, badged 55 TFSI, develops 340hp and 500Nm of torque. It's plenty quick, completing the 0-62mph run in 5.9 seconds.

Quiet at low revs, yet sporty sounding under load, the 55 TFSI delivers greater refinement than the 50 TDI, yet understandably doesn’t quite have the mid-range pull of its diesel counterpart. As a result, the 50 TDI can inspire greater confidence when overtaking and has a power delivery better suited to the Q8’s luxurious character.

Audi SQ8 and RS Q8 engines

Audi S Q8 (2020) engine

The SQ8 uses the same diesel engine as the SQ7- a 435hp 4.0-litre V8 with 900Nm of torque. Expect 0-62 to come in 4.8 seconds, while the top speed is limited to 155mph.

But it's not just vast acceleration off the line that you can expect from Europe's most powerful diesel engine. Thanks to that massive torque figure the SQ8 feels every bit as flexible as the RS car (if not a bit more) when it comes to overtaking or sprinting out of bends.

That's thanks to an electric compressor that helps build pressure for the twin-turbochargers at low engine speeds, all but eliminating the lag you would experience in a traditional TDI motor. This is powered by the 48v mild-hybrid system, which claws back energy normally lost during deceleration, effectively converting it into low end grunt.

As a result the SQ8's on-tap power feels instantaneous and bottomless. Its bassy rumble is purposeful but can't quite match the petrol V8 for drama - that said, it suits the diesel car's overall sense of unflappability.

The RS Q8 is the last word in speed when it comes to Audi's largest coupe SUV, of that there is no doubt, but for but it can't beat the SQ8 when it comes to usable, everyday performance. It also utilises the same chassis tech as the most powerful RS Q8 - electromechanical anti roll bars, rear wheel steering and Quattro all-wheel drive with the additional sport differential.

All of this gives the SQ8 the same sportscar-on-stilts feel as the SQ7, but turned up a notch to help it suit its more sporting coupe styling. 

The upshot of that is that the diesel powered SUV is supremely untaxing and easy to live with day-to-day. It lacks that final degree of decisiveness of the faster car, but you have to ask yourself in reality how often you will find a chance to use it.

That said, it's not quite as sharp or capable as the RS Q8. Up front, the RS Q8 uses the same 4.0-litre, V8 bi-turbo found in the Audi RS 6 and RS 7. Although the car weighs 2.3-tonnes, 600hp and 800Nm of torque flattens the 0-62mph run in 3.8 seconds. Top speed is an electronically-limited to 155mph, but can be extended to 189.5mph with an optional dynamic package.

It's fast, then. Epicly fast. Power delivery and noise aren't as manic or as shrieking as a Mercedes-Benz AMG V8. But ultimately, it's still very quick, and still pretty loud.

Audi Q8 gearboxes

The 50 TDI is mated with an eight-speed tiptronic gearbox. It’s smooth and decisive, yet also responds well to any manual override using the gearstick or steering wheel paddles.

Meanwhile, the 55 TFSI using a seven-speed dual-clutch S Tronic gearbox that feels sharper and more responsive, yet doesn’t quite have the silky smooth laid-back character of the tiptronic. 

Handling

  • Lower to the ground and more agile than the Q7
  • All cars come with air suspension as standard
  • Quattro all-wheel drive provides superb traction

Audi S Q8 (2020) cornering

The Q8 is billed as a sporty SUV, designed to cut through bends with greater agility than its Q7 sibling. Such intentions are clear from the outset, with the Q8’s steering feeling noticeably sharper than many rivals, requiring little lock to point the nose of the car in either direction.

Traction is predictably excellent thanks to the standard-fit Quattro all-wheel drive system that shuffles power to whichever axle has the most grip. It gives the Q8 a planted, and sure-footed feel ­– especially in slippery road conditions – that gives the driver huge confidence in the car’s ability.

Rear-wheel-steering turns up to 5 degrees in the opposite direction at low speeds (below 37.3mph) and up to 1.5 degrees in the same direction at high speeds (37.3mph and above). At low speeds, this reduces the turning circle by about a metre. At high speeds, it makes the car more stable. For instance, when changing lanes at 155mph on the Autobahn.

The end result is a car that feels surprisingly manoeuvrable around town – given its hefty dimensions – yet easily capable of swallowing long motorway cruises. Beware that some drivers may find the system takes a little getting used to, especially at low speeds, where the vehicle’s turning radius is smaller than expected.

Fitted as standard on the Q8, adaptive air suspension can adjust the vehicle’s ride height by up to 90mm using the drive select function. Placing the vehicle in its lowest setting reducing bodyroll (where the vehicle’s body leans out of a corner) and gives the Q8 a sportier feel, while switching it to the highest allows greater off-road capability.

Like many cars of this type, the Q8 is unlikely to venture any further off-road than a gravelly track. Despite this, all cars come with hill-descent control, automatically maintaining the vehicle’s speed up to 18mph on descents greater than 6%. Rest assured, for 99% of UK buyers, the Q8 will have more than enough off-road ability for their needs.

Official towing weights have yet to be released, but the Q8 is available with trailer assist software that automatically reverses the vehicle (and trailer) into a chosen spot with minimal input from the driver.

SQ8 and RS Q8 are tidy handlers

Audi RS Q8 rear tracking

The SQ8 utilises the same chassis tech as the most powerful RS Q8 - electromechanical anti roll bars, rear wheel steering and Quattro all-wheel drive with the additional sport differential.

All of this gives the SQ8 the same sportscar-on-stilts feel as the SQ7, but turned up a notch to help it suit its more sporting coupe styling. That said, it's not quite as sharp or capable as the RS Q8.

The upshot of that is that the diesel powered SUV is supremely untaxing and easy to live with day-to-day. It lacks that final degree of decisiveness of the faster car, but you have to ask yourself in reality how often you will find a chance to use it.

The 600hp of the RS Q8 is channeled through all four-wheels, although up to 85% can zing to the rear, while the front can handle up to 70%. Traction is biblical. Even when flicking down to second gear and stepping on the accelerator on greasy roads, no traction control lights are illuminated. Being really pinnikity, there is a slight lack of front end grip when really pushing.

It rides well on the softest setting, the air suspension able to cocoon you in comfort on nearly everything the roads can throw at you. Minor niggles from the road can be felt through the thick seats, especially on undulating surfaces with lots of little imperfections. But it does a fantastic job of smashing through bigger ones. With a car like this, it'd be unimaginable to create a car that doesn't fidget a little bit.

Put the great ride down to the standard adaptive air suspension as standard. Stiffer and lower than standard air suspension on the Q8, it automatically drops by 10mm at speed. From its highest setting to its lowest, is around 90mm.

The gearbox, and eight-speed auto, is sublime when really pushing hard. Upshifts are lightning fast making your neck jerk forward. Downshifts have a nice blip of the throttle on the way down too. In non R.S modes it can be hesitant to change down, even when you're using all the long throttle pedal has to offer. The paddles make for much better companions if you want to push on.

Audi S Q8 (2020) cornering, rear view