Audi SQ8 TDI 2020 Review - International

Diesel is a dirty word

The Audi SQ8 TDI can’t be sold in the US, where the German car-maker has pulled the plug on diesel-fuelled vehicles post Dieselgate, meaning consumers in the world's largest SUV market will be denied one of the fastest SUVs Audi has ever made.

Even back in its native Europe, Audi will have its work cut out to shift the SQ8 TDI. With threats of outright diesel bans in many major European city centres, no matter how clean the smooth new V8 turbo-diesel is, many buyers may simply be frightened off into purchasing thirstier, dirtier rivals.

Or they'll just wait for the petrol-powered SQ8 that's rumoured to be on the way.

That would be a shame, because back home in Australia the big new Audi SQ8 TDI couldn't be more relevant to the wants, needs and desires of the typical buyer in the market for a fast, premium SUV.

For evidence, just consider the numbers. I mean, who isn't impressed by a triple-boosted 4.0-litre V8 diesel that produces 320kW of power and manages to churn out a monstrous 900Nm of torque?

Then there's its range.

Brim the 85-litre tank and, thanks to the SQ8 TDI's 7.8L/100km average fuel consumption, you should be able to easily cover 1100km between refills – an astonishing feat for a large 2.3-tonne vehicle that can hit 100km/h in a claimed 4.8 seconds.

Set to land in Australia in the first quarter of 2020, the Audi SQ8 TDI is expected to command a sobering $50,000 price premium over the standard Q8 ($129,300 in both 3.0-litre V6-powered 50 TDI diesel and 55 TFSI petrol forms.

Priced at around $180,000, the SQ8 lands smack bang in the middle of a highly competitive performance SUV marketplace. Closest rivals should be cars like the BMW X6 M, Mercedes GLE 63 Coupe and the Porsche Cayenne S Coupe.

But none of these really get close in terms of price – both the BMW and Benz are $20,000 more expensive while the Porsche is cheaper by the tune of $14,000, it can only muster a weedy peak torque of 550Nm.

Yes, BMW’s quad-turbo 3.0-litre six-cylinder diesel X5 M50d is cheaper at $150K, but it delivers ‘only’ 294kW/760Nm and is slower. And while the same engine in the X6 costs $155K, the V8 petrol-powered X6 M50i is cheaper, quicker and more powerful, but a lot thirstier.

You might mention the V8-diesel-powered Range Rover here, but the Audi remains in another league for performance, mainly due to its torque – and the SQ8's pulling power is something you can't overlook because it dominates the driving experience.

When I asked one engineer how accomplished the SQ8, which has a towing capacity of 3500kg, is at hauling heavy loads, he just smirked and replied "you won't notice it, whatever you're towing".

Behind the wheel such a remark doesn’t sound so flippant, since the technically accomplished turbo-diesel, which is shared with the Audi SQ7, generates all its herculean thrust from just 1250rpm.

That means you could drive an SQ8 for weeks without ever seeing the other side of 2000rpm.

Think big-block V8 without the epic soundtrack, as engineers have largely dialled out the noise made by the silky-smooth 4.0-litre bent eight.

Earlier we said the SQ8 lifts its engine from the SQ7 and it does, but not the current one. The V8 diesel is shared with the facelifted version of the large Audi SUV, which won’t arrive here until closer to mid-2020.

That explains the addition of new belt-driven alternator mild-hybrid technology that can claw back around 8kW under braking, saving as much as 0.5L/100km on the combined cycle.

Like the SQ7, for an undisclosed price, Audi will add four-wheel steering to the SQ8 TDI's armoury, shrinking its turning circle in the city by more than a metre, boosting its agility on country roads and increasing stability at highway speeds.

A more ludicrous option now available (Audi Australia hasn't announced pricing for this yet either) is a mighty new 10-piston carbon-ceramic brake package that increases the front rotor size to 420mm and will surely appeal to autobahn users who need a little extra braking from its 250km/h limited top speed.

All Audi SQ8 vehicles ride on 21-inch rims as standard, but our test car rode on larger-still 22s. Speaking of external changes, aside from some moodier colours, the design of the SQ8 remains largely the same compared to the regular Q8, although inside you'll find glossy carbon-fibre in place of brushed steel or aluminium.

Climbing behind the wheel, the standard virtual cockpit digital instrument display now features 'SQ8' graphics, completing the changes over what remains one of the best -- if not the best -- cabins in any SUV in any price bracket.

As well as rear-steer and big wheels, our test car also came equipped with the Audi Sport-derived mechanical limited-slip differential that adds a final level of agility as it can channel 100 per cent of torque to either rear wheel.

With all this talk of rear-steer, carbon brakes and limited-slip diffs you might imagine Audi had morphed its range-topping SQ8 into a Cayenne Turbo-beater, but it doesn't take long to realise engineers have been more focused on boosting comfort than setting lap records at the Nurburgring.

It's important to note the Audi SQ8, while coming equipped with standard air suspension, misses out on the more sophisticated three-chamber air suspension of the Cayenne.

This means its air springs can't match the level of stiffness the Porsche SUV can and that results in perceptibly more pitch under acceleration and braking, plus a touch more roll.

To counteract the latter, the big Audi gets anti-roll stabilisation designed to significantly reduce body roll through bends by using electric motors-mounted on each sway bar to oppose the forces, so the SQ8's body still stays impressively level during hard cornering.

Other changes over the standard Q8 include lots and lots of recalibration of the adaptive dampers and stiffening of the suspension bushings for more precise steering feel.

The changes result in a marked improvement over the SQ7, but the SQ8 never feels less than a heavyweight and that's understandable when you consider it tips the scales at around 2365kg (without the driver).

Apparently the sportier, less practical SUV is actually heavier than the larger seven-seat SQ7 it shares its engine with – blame the Q8's cool but heavier frameless doors.

Pushing on and, despite not quite matching the agility of its Porsche rival, the Audi SQ8 demonstrates decent cross-country pace while the massive stoppers are never troubled by the speeds and masses involved.

What remains a joy is the SQ8's wonderful 4.0-litre oil-burner, which uses a small electronically-powered compressor to torque-fill from idle, helping spin up the first (of two) traditional turbos.

As we've mentioned, for most people most of the time, there will be little need to wake up the second bigger blower, which comes online at 2200rpm, but when you do so the SQ8 flies.

In normal conditions, the all-wheel drive quattro system proportions 60 per cent of the engine’s torque mountain to the rear wheels but, in extreme circumstances, a further 25 per cent can be directed to either axle to drag the big SUV out of slippery conditions.

To be honest, on our road-based drive it was difficult to feel either the all-wheel drive or limited-slip diff do its magic, such was the grip and traction afforded by our car's 285/40 tyres, which made wheel slip almost out of the question.

Amusingly, even the engineers who developed it admit the big, stylish SUV isn't really at home off the beaten track and you'd have to be pretty brave to venture off into the bush without a spare wheel (there's no spare as standard).

But if you do fancy getting the tyres muddy, the air suspension can raise the body out of harm's way to provide around 254mm ground clearance and Audi even claims the SQ8 can wade up to 500mm too.

Back on the road, questions remain over how comfortable the Audi SQ8 rides. The roads we drove on were far too smooth to accurately replicate the horrors of Australian black-top, but one little birdy (who signed off the chassis) told us Aussies should avoid the optional 22-inch rims if you savour a plush ride.

Another SQ8 gripe, which can also be levelled at the regular Q8, is the fact the big SUV is only really a four-seater -- despite measuring in at almost five metres long. The middle seat is too narrow for most adults and offers limited headroom, which is a bit pathetic considering its footprint.

Despite the fact the Audi SQ8 provides more than enough performance in the real-world, Audi Sport is rumoured to be almost ready to unleash an even faster 'RS' version of the Q8.

The Audi RS Q8 is expected to produce a monumental 500kW but only a ‘paltry’ 850Nm or so. That’s because the faster-still RS version will be powered by a plug-in V8 petrol powertrain.

Since Australia is lagging well behind in the infrastructure for plug-in vehicles, it means the torquier diesel-powered SQ8 TDI will remain the better, more relevant SUV.

There might be equally-stylish, faster-still SUV rivals that eclipse Audi’s flagship high-rider with their dynamics, but none of them wrap it all up in a more efficient package.

Indeed, it seems the Audi SQ8 is tailor-made for those Australians who yearn for a fast, stylish and efficient luxury SUV -- but, in our eyes at least, there's still one competitor that overshadows it.

If it were our money, we'd be tempted to sacrifice a whole heap of style to save a cool $20,000 by plumping for the equally luxurious, more practical and arguably better SQ7.

Either way, Audi wins for persevering with diesel when it comes to premium performance SUVs.

How much does the 2020 Audi SQ8 TDI quattro cost?
Price: $180,000 (estimated)
Available: First quarter 2020
Engine: 4.0-litre V8 twin-turbo diesel
Output: 320kW/900Nm
Transmission: Eight-speed automatic
Fuel: 7.8/100km (ADR Combined)
CO2: 204g/km (ADR Combined)
Safety rating: N/A