In the wake of the diesel-gate scandal, public scrutiny of Diesel engined passenger vehicles has been intense. It seemed that the diesel engine had been condemned. Both Porsche and Bentley have taken the decision to remove high-performance diesel engines from their ranges. Governments have also moved to make diesel ownership less attractive. It made us wonder whether there was a future for the diesel engine. Clearly, Audi thinks that there is with the announcement of the Audi SQ8 TDI!
Audi has re-geared its range in response to the changing markets. It now offers more petrol alternatives in segments traditionally dominated by diesel. The benefits of a diesel engine have always been superior economy and low-down torque. These qualities are being replicated in with a growing number of clever hybrid models. Using electronic motors, most manufacturers have been able to increase power and performance across the rev-range while also boosting efficiency.
Audi’s SQ8 TDI uses the best of both worlds; a twin-turbocharged, 4.0 litre V8 power unit with mild hybrid technology. The 48-volt system powers an electronic compressor which fills the turbo gap in the same way as Audi’s petrol units. Power is rated at 435 hp and a barnstorming 900 Nm of torque. All told, this makes the SQ8 a very quick machine. Power is routed through an eight-speed tiptronic gearbox. Audi quotes a 100 km/h sprint time of 4.8 seconds and a top speed limited to 250 km/h.
The technology does not take away from the fact that the SQ8 is still powered by diesel. After all, there are downsides. Despite Audi’s best intentions, the sound is industrial, not sonorous. Those quad-exhausts put out a consistent rumble, not a bad sound (and definitely indicative of the supreme pulling power) but it is unable to compete with similarly powered petrol engines. As a result, the SQ8 TDI lacks in the dramatics department. That said, the sound is subtle, something which might appeal to the type of buyers Audi hopes to attract.
The chassis is also helped technology. The SQ8 TDI is a near 2.5 tonne SUV. To control that weight and the new turn of pace, Audi has made air suspension standard all round. Options fitted to our test vehicle included all-wheel steering, the rear sport differential and electromechanical active roll stabilisation. The latter is particularly interesting, carried over from the Bentley Bentayga, the anti-roll bars actively decouple in a straight line to allow a more compliant ride. The combination of features makes for a well-controlled ride.
The Audi drive select system allows a variety of different settings from comfort through to dynamic modes. As with most setups these days, we found individual mode to be the best of all. Being able to isolate the characteristics, combining a comfort chassis setup with dynamic steering in traffic on a country road, gives the SQ8 an impressive range of skills. Our one criticism is that Audi’s drive select function can be a little difficult to navigate, buried in the central infotainment system. Switching between settings requires diverting your attention away from the road. At times, individual buttons might seem to provide greater accessibility.
No amount of chassis wizardry can help the SQ8 TDI escape the fact that it is a very heavy car, not much suited to narrow mountain roads. The combination of torque vectoring systems and all-wheel steering gives the SQ8 a fair run into the corners with little body roll. Grip is available but is limited by the laws of physics! Truth be told, most SQ8 TDI owners will use their vehicles on the highway or in the city. The majority won’t see this as a limitation.
The SQ8 TDI is instantly recognisable from the outside. Traditional Audi S-badge traits are present. These include a set of silver, brushed aluminium-effect wing mirrors, quad-exhaust pipes, larger wheels and a lower stance. The single-frame grille gets the same silver colouring applied to the frame. It is the traditional blend of subtle changes which are important to the overall feel of the car.
Interior comfort is typical of Audi. Very few changes have been made over the rest of the range. This is for good reason. The Audi interior works very well with comfortable seats incorporating air conditioning, heaters and massage functions. It has a head-up display and plenty of space in the rear. The only noticeable addition comes in the form of optional carbon fibre trim.
The Infotainment system is superb. The digital dashboard is clear with two views and information customised to preference. The traditional dual disks can be replaced at the touch of a button to reveal a full-sized sat nav screen. This frees the central display for something different.
The Audi SQ8 TDI will be available in Europe, Australia and Taiwan only. Demand dictates that Audi will not sell the SQ8 in other markets. German pricing starts from 102,900 euros and grows considerably, once you add some of the must-have options to the list (rear wheel steering, electromechanical active roll stabilisation).
Diesel is alive and kicking at Audi. The SQ8 TDI is proof of that. If you are after the fastest diesel-powered luxury SUV on the market then it is the best option.