deeply, and on the open road it loves to wind out. Its 200 hp is delivered almost silently, though at full

acceleration there's a reassuring roar. It's more powerful than previous Audi powertrains, though it isn't quite

as quick off the line as some comparably priced sedans.

The V6 is mated to a 5-speed Tiptronic transmission based on a design from Porsche. It can be operated either

as a silky-smooth automatic or switched to manual mode. Moved into a special gate, the driver upshifts or

downshifts for enhanced control. It's entertaining and particularly useful on winding roads and in the mountains.

A6 buyers have a choice of the front-wheel-drive configuration or Audi's legendary Quattro all-wheel-drive

system. A few years back, you had to have a big bank account to drive a Quattro, but since Audi reduced the price

on the basic Quattro package, we'd say it's a must. Quattro is a full-time all-wheel-drive system that is

constantly at work putting power to the pavement through all four wheels. It brings a sense of control and security

to the driver like nothing else.

Audi calls its Quattro system an "enabling" technology, referring to traction control systems on two-wheel-drive

cars as "disabling" technology because they work by reducing engine power until wheel spin is under control.

Now in the fourth generation of the Quattro system, Audi is way ahead of other companies in all-wheel-drive

technology. The key to Quattro has always been the use of three differentials that vary power distribution to all

four wheels, all of the time, at any speed. The latest system uses an electronic differential lock that operates on

both the front and rear differentials. This feature detects and limits wheel spin and redistributes drive torque

from side to side to take advantage of any available traction. This operates with the Torsen center differential

that distributes up to 65 percent of the traction to whichever axle has the most traction.

Quattro comes with a double-wishbone rear suspension, while front-wheel-drive A6s are equipped with a torsion-beam

rear suspension. The front-wheel-drive (non-Quattro) A6 models use Audi's FrontTrak traction control system, which

operates at all speeds to reduce wheel spin.