DIESEL is just as good as petrol. That is the message Audi Australia is sending to buyers as it pitches its new $86,700 A4 3.0 TDI V6 at the same price as the A4 3.2-litre FSI petrol V6.

Audi claims the 3.0 TDI V6 is the most powerful six-cylinder diesel engine in the prestige small-medium sedan class, eclipsing even Peugeot’s forthcoming 150kW/440Nm HDi 2.7-litre V6 for the 407. (The engine is currently only available in the 407 coupe.)

Compared to even the 3.2-litre FSI petrol V6, the TDI V6 is a bahn-stormer.

Developing 171kW at 3500rpm and 450Nm from 1400rpm, the TDI quattro is just 17kW shy of the 3.2 V6 but develops 120Nm more torque.

The latest-generation direct-injection diesel propels the A4 to 100km/h in a claimed 7.5 seconds, on its way to a governed top speed of 245km/h.

Significantly, the car will also return 8.4L/100km combined (according to a lab-based fuel-consumption test), enabling Audi to claim that the A4 will travel 750km on one tank of fuel. The TDI also meets Euro 4 emission standards.

Furthermore, Audi engineers have aimed to reduce noise levels both inside and outside the car, claiming the TDI V6 sets a benchmark in the segment for quietness.

Like all of Audi’s "V" generation engines, the TDI V6 has compact dimensions and weight, tipping the scales at 219kg and making it one of the lightest turbo-diesel six-cylinders in the world.

The camshafts, like the oil pump, are chain-driven for durability and longevity. The engine has common-rail technology, the latest piezo injection system and the turbocharger sits inside the engine’s “V” to optimise available space.

The turbo’s efficiency is enhanced by twin intercoolers running in parallel, keeping intake air temperatures down.

Like other quattro models, the TDI V6 features a permanent four-wheel drive system with self-locking centre differential mated to an electronic stability program. It is paired with a six-speed automatic transmission with a sequential-manual mode.

Apart from ESP, safety equipment also includes anti-lock brakes, brake assist, brake disc wiping system, electronic differential lock, dual front, side and curtain airbags and front seatbelt pretensioners.

Standard features also include climate-control air-conditioning, electric front seats with electric lumbar control, Bluetooth mobile connectivity, 17-inch alloys, front and rear foglights, sports suspension and acoustic rear parking sensors.

Volterra leather upholstery, burr-walnut trim, a multi-function sports steering wheel with paddle shifts, cruise control, 10-speaker Chorus CD stereo, auto dimming rear-view mirror, a trip computer, speed-sensitive power steering and automatic rain and headlight sensors are there, too.

As the volume model here, the A4 accounts for about 25 per cent of total Audi numbers and Audi Australia expects the 3.0 TDI to account for about five per cent of total A4 sales.