NEW YORK – The biggest, most-powerful Audi A4 ever will hit dealer showrooms in mid-September, says Audi of America Inc. Product Manager Carter Balkcom.

The all-new ’09 A4, available in 4-door sedan and station wagon variations, is longer, wider, roomier and, with two new engines, more powerful than its predecessor.

Balkom says despite additional standard equipment and other improvements, pricing for the new model will remain unchanged from the current generation, which starts in the low $30,000s.

Demand for the A4, which went on sale in Europe last April with a starting price of €31,670 ($49,930), is outstripping supply, an Audi AG spokesman says.

The new A4 is built in Ingolstadt and Neckarsulm, Germany. U.S. dealers already are taking orders, while Audi says there is less than a 30-day supply of the ’08 model, currently available only as a special-edition vehicle.

Despite the ’08 being in the seventh year of its production cycle, sales are running about 10% ahead of last year, Audi says, and the auto maker expects the outgoing model to essentially be sold down by the time the ’09 arrives in dealerships.

Like its predecessor, the ’09 A4 will be available with both 4-cyl. and 6-cyl. direct-injection gasoline engines, developed through Audi’s Le Mans racing program.

Direct-injection eliminates knocking in turbocharged engines that result from high-combustion chamber temperatures. Thus, Audi says its engines can operate at higher compression ratios with improved thermodynamic efficiency.

Balkcom predicts 80% of the A4s sold will be equipped with the 4-cyl. engine, which generates 211 hp and 258 lb.-ft. (350 Nm) of torque. When mated to the 6-speed manual transmission, Audi says 0-60 mph (97 km/h) acceleration is 6.5 seconds. The 4-cyl. mill mated to the 6-speed automatic with Tiptronic manual shifting has a 0-60 mph acceleration of 6.7 seconds.

The 3.2L V-6 direct-injection gasoline engine generates 265 hp and 243 lb.-ft (329 Nm) of torque and sprints from 0-60 mph in 6.3 seconds, while achieving 10% better fuel economy than the previous-generation A4, Audi says.

The suspension is completely redesigned for the ’09 model. Engineers repositioned the front axle farther forward and relocated the battery to the trunk, resulting in better front to rear axle-load balance. A sports suspension option offers firmer springs and shock absorbers and a lower ride height. Quattro all-wheel-drive is standard for the Avant wagon variant and optional for the sedan in North America.

Balkcom expects 75% of the A4s sold will be Quattro equipped, and about 5,000 of the Avant variant will be sold in a full year.