Audi A6 3.0 TDI and A7 3.0 TDI review | first drive

Canberra is no Le Mans and the road leading to Parliament House is certainly no Mulsanne Straight. No matter, Audi used the national capital to launch its race-bred turbocharged diesel engine in Australia.

Audi now features diesel power in all segments but the R8, with diesel sales last year taking up 43 per cent of the Australian market. The A6 already has a strong TDI presence in the market, with 53 per cent of buyers favouring an oil burner. The biturbo pair will be joined later this year by the SQ5 high-performance SUV.


The fuel efficiency places both models under the luxury car tax threshold of 7.0 litres per 100 kilometres, allowing Audi to gain a distinct price advantage over rivals. The A6 sedan has a manufacturer’s list price of $118,800, while the A7 Sportback carries an MLP of $148,600.

Both vehicles share many features with other high-end Audis. For example, the A6 sedan includes18-inch alloy wheels in 10-spoke V design, Audi drive select with efficiency mode, Audi music interface and Audi parking system with rear-view camera.

Bose surround sound leads the way for a Bluetooth interface with music streaming, electric front seats are clothed in Milano leather and have driver memory function, MMI Navigation plus features retractable screen and touch pad and Xenon plus headlights show the way at night, while an electric sunroof brings enjoyable weather outside inside.

The A7 Sportback adds 19-inch alloy wheels in 10-spoke design, while four-zone deluxe air-conditioning puts occupants seated on premium quality Valcona leather upholstery at ease.


The new 230 kW 3.0-litre TDI biturbo V6, which owes much of its high performance technology to the Le Mans 24 Hour-winning Audi engine, can now be found in the A6 sedan and A7 Sportback.

‘Fast and frugal’ is the biturbo byword with both vehicles sprinting to 100 km/h from rest in a tick over five seconds – making the A6 sedan, at 5.1 seconds, the quickest diesel-powered vehicle in Australia – and fuel consumption down at 6.4 litres per 100 kilometres with carbon dioxide emissions of 169 g/km.

In the process, a sound actuator in a side channel of the exhaust orchestrates a glorious symphonic note in tune with the robust performance of the cars. Essentially a loudspeaker, the instrument produces a sonorous accompaniment to engine revs rising all the way to 5200 rpm. Further ‘philharmonic’ is carried into the passenger cabin via the vibrating windscreen which dances to the deep-throated note of the motor when hurried along. Nothing ‘largo’ here.

The heart and soul of the pair is the biturbo engine, which features, as its title suggests, two water cooled turbochargers connected in series. A switchover valve directs intercooled air to a small turbo at low revs, with a large charger performing pre-compression. From 2500 rpm, or thereabouts, the valve begins to open and the small charger shifts most of its workload to its big brother. Between 3500 and 4000 rpm the valve opens fully, the large charger taking on all the work.

The engine itself has come in for modifications, with the cylinder head cooling, the timing and lift of the intake cam shafts, the pistons and their oil jet cooling all being improved. A special coating reduces the friction of the piston pins, while plate honing and laser exposure, are used during the fabrication of the engine block at the plant in Gyor, Hungary.

The common-rail fuel system develops up to 2000 bar of pressure and injects as many as eight partial amounts of fuel into the cylinder. The regulated oil pump and the water pump have been optimised for maximum efficiency. The top-of-the-line TDI provides peak torque of 650 Nm from 1450 to 2800 rpm.


At idle, the ‘dieselness’ (i.e. the distinctive rattle) of the engine is indiscernible, but tramp on the pedal and the ‘orchestra’ fires up through the aforementioned exhaust sound system. Wagner would have approved. A heavy foot once or twice had the engine hesitant to respond, which we put down to the electronics of engine management rather than turbo lag.

An eight-speed Tiptronic transmission and quattro all-wheel drive make sure both biturbos are model performers in either bustling city driving or on the open road, a fact that was borne out by a launch test drive between Canberra and Sydney. Parking is a breeze thanks to front and rear cameras, and electric tailgate operation makes for easy access to a generous cargo area, the latter being a welcome feature of both vehicles.


The state-of-the-art technology results in immensely powerful performance.


A6 3.0 TDI quattro 230 kW sedan: $118, 800
A7 3.0 TDI quattro 230 kW Sportback: $148,600

Audi A6 TDI Quattro

Price: from $118,800 driveaway
Warranty: 3 years/unlimited km
Engine: 3.0-litre 6-cyl, 230kW/650Nm
Transmission: 8-speed auto, AWD
Body: 4915mm (L); 1874mm (w); 1455mm (h)
Weight: 1790kg
Thirst: 6.4L/100km 169g/km CO2

Audi A7 TDI Quattro

Price: from $148,600
Warranty: 3 years/unlimited km
Engine: 3.0-litre 6-cyl, 230kW/650Nm
Transmission: 8-speed auto, AWD
Body: 4969mm (L); 191mm (w); 1420mm (h)
Weight: 1850kg
Thirst: 6.4L/100km 169g/km CO2


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