ULTIMATE A6; Audi unleashes its M5 fighter.(News)

Byline: WES RAYNAL

A couple of days before Audi launched its new TT under Berlin's Brandenburg gate ("TT: The Sequel,'' April 17), we got a chance to spend some time in the company's newest hot rod, the S6. The S6 is derived from a simple yet effective formula: Take a fine midsize Audi sedan, stuff it full of Lamborghini Gallardo V10, and turn 'er loose.

Displacing 5.2 liters, the V10 is the second in a production Audi, and carries over almost intact from the S8 ("Cruise Missile,'' Jan. 16), with slight modifications to the intake and exhaust. Lamborghini builds the block, pistons, rods and cylinder heads, while Audi does its own ignition and FSI direct fuel injection. In the S8 the engine produces 450 hp and 398 lb-ft of torque. The S6's numbers are 435 hp with torque staying the same. Power in the S6 is good enough to propel the near-4400-pound car to 60 mph in 5.1 seconds, a half-second slower than the BMW M5, to which comparisons are inevitable.

Snow, sleet and freezing rain stubbornly refused to leave Germany even as spring tried to make its presence felt-temps in the 60s one day, in the 30s the next. With summer tires mounted on the S6, the conditions made for a somewhat cautious drive. Audi calls the S6 a sports car for everyday use, and we were about to find out if that is the case.

We tiptoed down the autobahn (well, we did manage to crack 100 mph a couple of times) and on two-lane roads from Stuttgart to Audi's second home in Neckarsulm. The Neckarsulm facilities date back to the NSU days (German automaker NSU built its first car in 1905; Volkswagen bought the company in 1969), and today it is where customers can take European delivery of their Audis at the newest Audi Forum.

We did get enough decent seat time in the S6 to learn that, like the S8, this Audi is less extreme than an M5 or a Mercedes-Benz AMG car. The Audi doesn't explode off the line like the BMW, but it does have a gracefulness to it the M5 lacks. Acceleration builds firmly and ultra smoothly as the engine revs climb-90 percent of the torque is available from 2300 rpm to 5000 rpm.

At idle the V10 produces a steady, low rumble, turning into a refined, smooth growl as the revs build: Boot the gas pedal and you know something special is happening, but nothing garish. It sounds like a muffled version of Audi's famed R8 Le Mans racer, not to be confused with the new R10 diesel, which makes little sound at all.