Over the 30 years since the debut of the first quattro, Audi has gradually increased its technology lead in the sphere of all-wheel drive. Not that the Ingolstadt engineers are content to rest on their laurels. The company is now presenting a new evolutionary stage - quattro drive with crown gear center differential. This technology, which is even more efficient, precise and high-performance than the previous concept, is now available in the new Audi A6 and A7.

The self-locking center differential in the quattro driveline, positioned immediately at the transmission output, has the task of distributing the engine torque between the two axles in defined proportions. If one wheel of an axle starts to slip - for instance on a slippery surface - the differential without delay diverts most of the propulsive power to the axle achieving better traction.

The new center differential from Audi follows an innovative principle. Its cylindrical housing is driven by the transmission. Inside it there are two rotating crown gears that owe their name to the crown-like design of their teeth.

When the front and rear axles are rotating at exactly the same speed, the two crown gears run at the same speed as the differential housing. But because of the special design of the teeth, they have different numbers of teeth and meshing points at different diameters. The lever effects are therefore unequal. With the basic torque split, 60 percent of the engine torque flows to the differential for the rear axle and 40 percent to the front. This permits very good traction and driving dynamics on dry pavement.

If the front wheels encounter a patch of snow, the speed of the front axle will momentarily rise. This produces a speed difference between the two crown gears and the housing. The self-locking effect in the crown gear center differential now immediately diverts the drive torque to whichever axle achieves better traction. Up to 85 percent of the drive torque reaches the rear wheels. In the opposite scenario - if the rear axle finds less grip - the same happens in reverse; now up to 70 percent of the torque is diverted to the front axle.

With this broad torque distribution range the newly developed crown gear center differential surpasses its predecessors - traction becomes even better thanks to increased locking effect. Forces and torques are redistributed permanently without any time lag, and absolutely consistently. The driver can easily handle the situation. No control electronics or electromagnetic or hydraulic actuation are needed. The purely mechanical operating principle guarantees maximum efficiency and no-delay response.

This new crown gear center differential impressively demonstrates the constant progress being made by quattro drive technology. It also increases Audi's lead over its competitors.

To test drive the finest all-wheel drive vehicles on the road, contact one of our Audi Brand Specialists at 303-238-8101 and ask about the 2012 A6 and A7.