If you're only into the A6 for the Audi nameplate, there's a tepid base version for you. But if you're seeking ultra-high economy or muscular performance, there are three other editions cued up, all with forced-induction engines.
The base A6 is the dispassionate front-drive, CVT model. The powerplant isn't the fault. The 2.0-liter turbo-4 drops 220 hp with lots of low-end grunt, but it can only do so much in the A6's big body and with the lackluster transmission. Add all-wheel drive and the A6 with the turbo-4 adopts an 8-speed automatic with paddle shift controls. It's a much better option, and 0-60 mph times fall in the low 7-second range.
When it was launched, we strongly recommended the 240-hp turbodiesel V-6. With a narrow powerband, an 8-speed automatic and all-wheel drive, it turned in smart performance numbers and excellent fuel economy. Then VW Group was found to have cheated on emissions testing, and it all was rendered moot. If you own one of these vehicles, Audi has set up a web site for buyback and repair information.
From there, Audi ups the ante with a supercharged V-6. The V-6 puts out 310 hp through an 8-speed automatic and all-wheel drive, which is set to a fixed 40:60 power split. Its 60-mph times clock in around 5.4 seconds, with a top speed of 130 mph. It's a happy co-conspirator in this form, with the automatic snapping off quick shifts by itself, or timed with the inputs on the shift paddles.
There's still another version to consider. Audi drops its 420-hp, 4.0-liter twin-turbo V-8 in the A6 and calls it an S6. The S6 also gets a 7-speed dual-clutch transmission, better brakes, a stiffer suspension, and can be fitted with a torque-vectoring rear differential that can shift power between the rear wheels. Capable of 60-mph runs in 4.5 seconds, the S6 has supremely satisfying handling with reasonable ride quality even though it rides on summer tires and 21-inch wheels.
If possible, avoid Drive Select. It switches driving modes from comfort to sport, changing up the car's shift patterns, throttle delivery, steering weight, and damping. Its sport mode dumps weight in the steering without adding precision, and there's no mode we think is programmed to show off the car's best traits.