Depending on vehicle speed and Drive Select orders, the dynamic steering varies its ratio by up to 100 percent. In town, it's light and direct but not quite as extreme as its lightning-fast counterpart from Munich. Through switchbacks, it feels meatier but still doesn't require a change of grip on the steering wheel. On the highway, it's relaxed, thanks to a languid four turns lock-to-lock. What makes this system special is the dialogue between the steering and the stability control. Lift-off oversteer, for instance, is automatically corrected by a small dose of momentary opposite lock. Understeer is mellowed by a brief modulation of steering angle that reinstates grip--and confidence. In most situations, supplementary brake and throttle intervention isn't even necessary.
The chassis DNA of the new A4 follows that established for the A5. The redesigned multilink front suspension makes room for a more precise steering rack, which is mounted low and close to the wheels. By having the clutch and the differential (or the torque converter and the differential, in cars equipped with an automatic transmission) swap positions, there was a gain of a precious six inches in length, which was devoted to pedestrian protection, crash performance, and wheelbase extension.
The four-link independent rear suspension was largely derived from components fitted to the A6 and the A8. Front and rear subframes ensure optimum rigidity and precision. Quattro all-wheel drive splits the torque between the axles unevenly at 40/60 percent front to rear, but if need be, up to 90 percent can be directed to the front wheels. Even power oversteer is no longer a foreign concept, thanks to a revised center differential that can also dispatch 90 percent of momentum to the rear wheels. Switch off ASR (traction control) but keep ESP (stability control) on duty for the best mix of slides, smiles, and safety.
The new V-6 consumes ten percent less fuel than the outgoing version, and it clips 0.5 second off the 0-to-62-mph acceleration time (which is now 6.2 seconds, according to Audi). High-tech innovations include a dual-stage intake valve-lift system, a substantial reduction of frictional losses, and a lightweight, low-noise chain drive. The diesels boast common-rail injection for reduced noise and AdBlue (similar to Mercedes-Benz's Bluetec) cleansing for reduced emissions. The 3.0-liter V-6 rated at 240 hp and 369 lb-ft of torque is heralded by Audi "as the cleanest diesel in the world," since it even meets tough California emissions standards. Also in the works are two extra-frugal A4 TDI/TFSI models featuring aerodynamic modifications, a longer-legged transmission, and special low-rolling-resistance tires, but don't look for these models to come to the States.
We drove the new A4 on the Italian island of Sardinia, which is famous for its beaches and mega-expensive resorts but sadly not for the quality of its second-gear back roads. On predominantly washboard tarmac, the difference in ride between the comfort and the dynamic settings was as stark as the difference in visibility between a lunar eclipse and a power failure in a coal mine. The standard sixteen-inch wheels might have been a little more spine-friendly, but for maximum cushiness you definitely don't want to specify the lowered and tightened sport suspension fitted to our test car. At least our A4's continuous damper control offers a wider range of damping settings than the TT's magnetic ride control.
The biggest single surprise was the new dynamic steering, which works much better than the black-and-white active steering offered by BMW. Audi chose a totally homogenous calibration, and it's neither too quick in town nor too heavy and slow on the autostrada. More to the point, the transition between two-finger easy and two-hands firm is progressive and unobtrusive.