Audi A6 and A7 3.0 TDI Biturbo 2013 Review

We’re already quite familiar with the current Audi A6 and A7 model ranges, which have both been with us in one form or another for some time, comprising the usual selection of petrol and diesel engines, all offering the expected levels of ‘Vorsprung’ synonymous with the brand.

Then Audi goes and pulls an unexpected performance rabbit from its corporate hat, and it comes - perhaps to most - in a most unexpected form.

There are no S or RS badges here and no screaming petrol V8. In fact, there’s no petrol power to speak of at all. And no, this isn’t some fan-dangled new-age hybrid hypercar or all-electric rocketship, it’s one of the oldest forms of combustion known to the motoring world, albeit with a 21st century twist.

What we’re talking about here is diesel power in all its crank-twisting glory and it’s fair to say the 3.0-litre twin-turbocharged (Biturbo, in Audi speak) V6 crammed under the bonnet of the A6 and A7 packs an adequate set of figures: 230kW and 650Nm, if you don’t mind!

As we said when we first sampled the engine last year at the global launch of the SQ5 super-SUV, which arrives here mid-year, it’s an impressive output from a relatively compact unit and eclipses figures that not too long ago would have been the exclusive domain of large-displacement petrol V8s.

In fact, in the A6 sedan, the engine provides enough motivation to accelerate from standstill to 100km/h in just 5.1 seconds, making it the fastest diesel-powered vehicle in Australia.

Not to be outdone, the A7 Sportback is just two-tenths of a second off that pace, hitting triple figures in only 5.3 seconds - or around the same as BMW’s best diesel effort, the 535d.

From the cockpit the needle on the tachometer appears to move slowly compared to that of the speedo. Sure that’s due in part to the fact that diesel engines rev more slowly than petrols, but it’s also a sure sign that Audi’s LeMans-inspired Biturbo technology offers enough torque to tear the asphalt from the road.

Lag? Well there isn’t much to speak of. The only time we encountered any at all was when jumping back on the throttle just before coming to rest, and in truth it felt more like the electronics figuring out what they were meant to be doing as opposed to straight-up turbo lag.

The high-performance TDI engine produces an extraordinary bass note with the assistance of what Audi calls a sound actuator, which combines an exhaust-mounted ‘speaker’ and a small subwoofer of sorts set in the plenum chamber beneath the windscreen (it actually uses the windscreen as the cone of a ‘speaker’).

The result is a resonance not unlike that of a V8, and in case that’s not your thing, the good news is that it can be switched off via Audi’s MMI settings.

But back to that fabulous engine. Under acceleration the double-huffed V6 diesel offers impressive mumbo and the bulk of it is delivered so low in the rev range that you’d only ever see the tachometer needle spin skyward if you were overtaking, or out for a bit of fun.

Fun? Yes, fun - from a diesel. It probably sounds like a misnomer, but the rate at which this stonkingly powerful engine delivers its full whack of twist (from as low as 1500rpm) means you seldom have to use high engine speed to achieve satisfactory acceleration.

The silky eight-speed automatic transmission means Audi’s 3.0 TDI Biturbo simply flattens hills and demolishes overtaking manoeuvres. Thanks to grippy quattro all-wheel drive, it’s also no slouch through twisty country back-roads, where torque and traction combine to full effect.

And what’s better still is that thanks to revised friction coatings, precise injection techniques and the cooperation of a small and large turbocharger Audi Australia’s first Biturbo model achieves fuel economy averages that rival a hybrid.

On test we achieved 6.5L/100km - just 0.1L/100km more than the ADR combined figure – and the official CO2 emissions rating is just 169g/km.

The lean numbers mean Audi’s A6 3.0 TDI Biturbo sedan and A7 3.0 TDI Biturbo Sportback escape the clutches of Luxury Car Tax (LCT) to be priced at $118,800 and $148,600 plus on-road costs respectively.

For your coin the equipment inclusions on the A6 3.0 TDI Biturbo sedan extend to 18-inch alloy wheels, Audi drive select (with efficiency mode), Audi music interface, Audi parking system (with rear-view camera), a BOSE surround sound audio system, Bluetooth telephony and audio streaming, convenience key, electric front seats with memory function (driver’s side only), an electric glass sunroof, MMI navigation plus with retractable screen and touchpad controller, Milano leather upholstery and Xenon plus headlights.

The A7 3.0 TDI Biturbo Sportback adds 19-inch alloys, quad-zone climate-control, Audi parking system (with front and rear camera), electric tailgate function and high-grade Valcona leather upholstery.

Otherwise, mechanical, packaging and equipment levels are similar to that found in the derivative models, each of which have been sampled previously. (Click here for reviews of the Audi A6 and Audi A7)

Both the Audi A6 3.0 TDI Biturbo sedan and A7 3.0 TDI Biturbo Sportback sit atop their respective model ranges and are on sale from today.

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