Audi SQ7 TDI: Most powerful turbodiesel SUV around

INGOLSTADT: Audi is determined to promote diesel power to the max despite being embroiled in the Dieselgate scandal. It has just announced the biturbo V8-engined SQ7 TDI that it claims is the most powerful diesel SUV.

The engine makes 420hp and 900Nm, allowing the SUV to sprint from standstill to 100kph in 4.8s and onwards to a top speed of 250kph.

In terms of outright pace and speed, the fastest SUV title goes to the petrol-fuelled 600hp/900Nm Bentley Bentagya SUV which can hit 0-100kph in 4.1s with a top speed of 301kph.

The SQ7 TDI features a world first by having an electric powered compressor that Audi said removes turbo lag and allows the engine to be immediately responsive.

While immensely powerful, Audi said the SQ7 TDI is also easy on fuel consumption with combined fuel consumption of 6.2l/100km, which is equivalent to the figures for a six-cylinder engine.

The 3,956cc 4.0 TDI has been redesigned from the ground up. It combines best-in-class performance with impressive efficiency credentials through the use of two exhaust-gas turbochargers which are activated selectively according to the concept of sequential charging, since exhaust gas only flows through one turbocharger at low and intermediate load. The second turbine is only activated at higher loads. The electrically powered compressor (EPC) augments the work of the two turbochargers, particularly in the lower engine speed range, providing for responsive off-the-line performance.

48-volt electrical system

The electrically powered compressor is placed in the air path downstream of the intercooler, close to the engine. Because the compressor does not require any exhaust-gas energy to develop boost, it can be used at any time, thus making it the solution for the traditional weaknesses of the classic exhaust-gas turbocharger.

The compressor provides the engine with the boost energy needed for the dynamic delivery of power in less than 250 milliseconds. Driven by a compact electric motor, its compressor wheel spins up to 70,000 revolutions per minute. The 4.0 TDI thus develops its immense power immediately, with no perceptible lag.

The power for the compressor, which reaches a maximum of 7 kW, is provided by the 48-volt electrical subsystem which uses lithium-ion battery mounted beneath the luggage compartment.

The Audi valvelift system (AVS) is also making its debut in a diesel model from Audi. The inlet and exhaust cam shafts each have two cam contours per valve. On the inlet side, one cam contour supports starting off in conjunction with the compressor, while the other optimises cylinder filling and thus power at high engine speeds. The AVS system on the exhaust side enables activation of the second exhaust-gas turbocharger.

The sequential charging system controls the two exhaust-gas turbochargers so that only one turbocharger is used at low engine speeds. The second is activated additionally at higher loads and engine speeds. The customer benefits from very good torque delivery and dynamic response across the entire engine speed range.

The SQ7 TDI uses a redesigned eight-speed Tiptronic changes gears more quickly and efficiently, and at high speeds allows coasting at idle.

The maxim of lightweight construction also applies to the suspension – its links are made primarily of aluminium. Electromechanical power steering, the Audi drive select driving dynamics system and adaptive air suspension with S-specific tuning are standard. Lightweight carbon fibre-ceramic discs will become optionally available shortly after the market launch. Audi offers the SUV with 20-inch wheels on 285/45 tyres, with options up to 22 inches.

Also optional upgrades are all-wheel steering and sport differential.

Audi offers the SUV with a choice of either five or seven seats.

The SQ7 TDI offers a wide range of 24 driver assistance systems to help drivers travel safely, fuel-efficiently and comfortably. The predictive efficiency assistant, for example, provides additional information in the instrument cluster to help the driver save fuel. The standard Audi pre sense city – an anticipatory warning and emergency breaking function for avoiding accidents and protecting pedestrians – makes the SQ7 TDI even safer.

The adaptive cruise control with traffic jam assist relieves the driver in slow-moving traffic on well-paved roads by taking over the steering in many situations. The predictive ACC enables the anticipatory adjustment of driving speed to the route and speed limits, such as when entering towns.

In Europe, the Audi SQ7 TDI can be ordered beginning spring 2016. It will be offered in Germany for a base price of €89,900 (RM407,000).