Saying they will replace current E320 models in dealerships soon, Mercedes-Benz debuted a new 2006-model E350 sedan and wagon in Chicago. Powered by a new-generation 3.5-liter/268-horsepower V-6 engine that features four valves per cylinder and variable valve timing for both intake and exhaust valves, this also marks the first time Mercedes has used double overhead camshaft technology on its V-6 engines. The E350 sedan boasts a new seven-speed transmission which helps improve acceleration and also allows greater flexibility in adjusting shift points as needed for lower engine speeds (reducing fuel consumption and minimizing noise), skipping gears as required -- up to three gears at once when downshifting rapidly. The current E-Class lineup represents about 25 percent of total Mercedes sales in the United States. Click to watch the Mercedes-Benz video.