The Mercedes and the Audi are available only with manu-matic transmissions, but the BMW can be ordered with a manual, a sequential manual, or a manu-matic. While you must use the shift levers to effect manual changes on the BMW and Mercedes automatics, the Audi has steering-wheel buttons, which are a real advantage on challenging roads. Although the adaptive autoboxes are pretty good at responding to any variation in driving style, the comfort-oriented E-class in particular prefers early upshifts and late downshifts. It also has the slowest and least progressive throttle, a relatively passive gearbox, and an engine that does not particularly like to rev but, ironically, needs to be revved to deliver.
Despite the dramatic difference in character, the Mercedes is almost as quick as the Audi. On smooth blacktop especially, the E-class stays right on the tails of the other two cars. True, it has woolly controls and a relatively passive drivetrain-but it hangs on like a terrier, despite lots of yaw and roll, howling tires, and stability control that's working overtime. On rough pavement, however, it manages to combine a jittery ride with emphatic body movements and steering that feels light and lifeless. Without Airmatic suspension, this particular specimen sacrifices a core Mercedes quality: best-in-class comfort.
The BMW feels more tied down and more focused. Our 530i was the handling hero yet did a sterling job in compensating for long undulations and low-frequency irritations, as well as providing a reasonable low-speed ride. The AS/ARS package adds dynamic delight to this spine-friendly behavior. Thus equipped, the BMW combines quick steering with the art of total body control, along with more grip than 90 percent of drivers are ever likely to need.
The Audi is less tactile and less sensuous but every bit as competent. For a start, the A6's all-wheel drive can make a big difference in foul weather or on slippery roads. Having said that, Quattro would be more entertaining dynamically if Audi decided to change the torque split from 50/50 to a clear-cut rear bias. The steering is light and linear, but the turning circle is overly large, especially compared with the highly maneuverable Benz. The brakes are, at least subjectively, the best of the lot. They decelerate the car with vigor, they are easy to modulate, and they remain unperturbed even when you're giving them hell.
The new A6 is light-footed and deceptively quick. The Audi does have one big flaw, however. The suspension feels harsh and brittle, and it doesn't really matter whether the car is traveling at 25 or at 65 mph. You can tell that the engineers wanted to create an emphatically dynamic sedan, because they also fitted thinly padded, body-hugging seats, not enough sound-deadening material, and extra-fat antiroll bars.