2005 Audi A6 4.2 Road Test

With 335 horsepower fed to all four wheels through a six-speed autobox, a long duration behind the wheel may not be long enough.

Audi's robust 4.2-litre (255 cu in) powerplant spins out some of the smoothest, most refined power one could wish for. (Photo: Rob Rothwell, Canadian Auto Press)

Audi's robust 4.2-litre (255 cu in) powerplant spins out some of the smoothest, most refined power one could wish for. Fortunately, the refinement in operation doesn't rob the mill of its vocal cords. Under routine operation, a sweet V8 note percolates just below the surface, but stand on the throttle and a genteel, world-class V8 growl will greet the eardrums of the performance-minded.

Complementing the authoritative power of the A6's engine is an outstanding level of refinement highlighted by a smooth shifting, quick-to-react six-speed automatic transmission. Although BMW and Mercedes now tout a seven-speed autobox, the six-speed Tiptronic manual-mode unit in the A6 delivers remarkable versatility with the right gear at the right time. Shift points are

Audi claims a spirited 0 to 100 km/h time of just 6.2 seconds for the 1,880-kg (4,136-lb) A6 4.2. (Photo: Rob Rothwell, Canadian auto Press)

well matched to the engine's torque curve and are never protracted or delayed.

With six gears to wind out, the revs rise and fall at a surprising rate while the electronic speedo swings quickly into triple digits. Audi claims a spirited 0 to 100 km/h time of just 6.2 seconds for the 1,880-kg (4,136-lb) A6 4.2. Combined with blistering off-the-line acceleration and relentless Quattro-drive traction is abundant passing power. Regardless of the vehicle's speed, one of its six gears will place the punchy V8 into its broad-range sweet spot to ensure the maximum torque of 309 lb-ft is quickly delivered. Output of this magnitude is very effective at instilling driver confidence when jostling with the big rigs on mountain highways.