Audi S6 and S7 to arrive this fall, sportier RS6 and RS7 later

High-performance Audi variants on the way

The 2013 Audi S6 arrives in the fall, and the RS6 after that..

The coming Audi S6 and S7 are more exciting than the existing A6 or A7, but not quite as thrilling as the RS6 and RS7 that will come after them. They're in the middle, but far from middling.

The S6 sedan and the S7 fastback will arrive in showrooms this fall—late September or early October—with more power, better steering and handling and even better seats than the A6 and the A7 with which they share most of their structure. But we can be almost certain that there will be even more powerful, more sporty versions of these two when the RS6 and the RS7 arrive. So it's a great time to be in the market for an autobahn supersedan.

The heart of the S transformation is the new gasoline direct-injection, 4.0-liter, twin-scroll twin-turbo V8. In S guise, this engine makes 420 hp and 406 lb-ft of torque, a considerable jump from the 3.0-liter supercharged V6 in the A6 and the A7. This same engine will be used in the S8, which arrives in showrooms at the same time but with 100 hp more, thanks to some computer software changes and a twin air-intake system instead of the S models' single air intake. In the Bentley Continental, this engine makes 500 hp, so we can surmise that this is what we'll get in the RS6 and the RS7.

Audi proudly points out that the 420-hp V8 gets 25 percent better mileage than the last S6 thanks to “cylinder on demand,” which seamlessly deactivates four of the engine's eight cylinders at normal cruising speeds. (European models get start/stop technology, but U.S. models won't because the EPA driving cycle does not credit start/stop as a gas-saving feature.) Of course, one big reason for the increase in fuel economy is that the previous S6 was powered by a 5.2-liter Lamborghini V10.

The interior of the 2013 Audi S6..

Power is routed through Audi's seven-speed S tronic automatic and then to all four wheels. All U.S. S6 and S7 models will come with a sport differential in the rear that can vector torque to either rear wheel for better performance.

All of this rides on cushioning air shocks that lower the ride 10 millimeters compared with the A6/A7 versions. And you get a choice of 255/40 tires wrapped around 19-inch rims or 265/35s on 20s.

We drove both the S6 and the nearly identical—except for the rear roof—S7 fastback and found them to be perfect for the 170-mph autobahn while hauling of four or five people. U.S.-spec cars will be only slightly slower, as our top speed is electronically limited to 155 mph.

Off the line, Audi says to expect 0 to 60 mph in 4.5 seconds using launch control, though some at Audi suggest that you can get a 4.1-second run without launch control. Add a tenth for the slightly heavier S7.

After launch, the cars have no trouble getting up to 150 mph, despite their hefty curb weights of 4,398 pounds and 4,508 pounds, respectively. While these cars do have aluminum hoods, roofs, fenders and deck lids, the spaceframe is still steel, which explains some of the heft. At full throttle, flaps in the exhaust open up for a little more engine sound, but there is not much.

As you transition from autobahn to autostrasse, the airbag suspension can be fine-tuned to your needs with Audi's Drive Select system. It allows for four basic settings: auto, dynamic, comfort and individual. Each setting adjusts for throttle response, shift points, adaptive air suspension, quattro sport differential and the amount of boost for the electromechanical steering. Within the individual setting, you can further refine your ride and handling experience.

At slower-than-autobahn speeds, when the cylinders are deactivated, there is almost no indication of it outside of a notation on the instrument cluster. Audi includes active motor mounts to eliminate any trace of rough operation, along with speakers inside the cabin to produce an acoustic noise cancellation that pumps in whatever decibels are missing and cancels out any unwanted four-banging engine noise.

Combined with perfect rev-matching on downshifts, you hear almost nothing from the engine when you drive. This might be an inconvenience if you were driving aggressively through twisting Bavarian hills, as we did on our first day in the cars. With less acoustic feedback and near-perfect rev-matching, we had to check the instruments to see what gear we were in and to verify that the transmission had downshifted or upshifted.

With tightened-up airbags, the cars were not at all difficult to hustle through the hills, despite their mass, but no one is going to look at these as track cars they way they do the BMW M5 or the Mercedes-Benz E63 AMG.

Instead, Audi lists competitors as the BMW 550i xDrive and the Mercedes E550 4Matic, both within a handful of horses, pounds-feet and seconds in 0-to-60-mph times. In that company, the S6 and the S7 might be the sportiest, certainly in a straight line to Munich and back.

Look for pricing to be more than $70,000 for the S6 and less than $80,000 for the S7.

2013 Audi S6/S7

ON SALE: September

BASE PRICE: $70,000/$80,000 (est)

DRIVETRAIN: 4.0-liter, 420-hp, 406-lb-ft twin-turbocharged V8; AWD, seven-speed automatic

CURB WEIGHT: 4,398 lb/ 4,508 lb

0-60 MPH: 4.5 sec/ 4.6 sec (mfr)

FUEL ECONOMY (EPA): 25 mpg