Where the old 3.2 V-6 was a single-overhead-camshaft design with three valves per cylinder, the new engine has dual overhead cams and four valves per cylinder. Its variable-valve phasing on both the intake and exhaust cams reduces emissions, as well as increases fuel economy and power output. Tumble flaps in the intake passages and dual-stage intake manifolds further improve efficiency and give it 258 pound-feet of torque between 2,400rpm and 5,000rpm, a broad, flat torque curve. Horsepower is rated at 268 at 6,000rpm.
Mercedes-Benz's newest innovation, its 7G-Tronic transmission, uses seven gears, more than most contemporary cars' five- or six-speed automatics. Individual gear ratios are spaced closer together for more seamless performance, while the overall gear-ratio spread is wider, for improvements in acceleration from lower low gears and highway fuel economy from higher high gears. That said, EPA-rated fuel economy is only 19mpg in the city but a more acceptable 27mpg on the highway.
Sophisticated computer-control algorithms with adaptive logic learn each driver's driving style and adjust shifts accordingly, but the transmission can also be manually shifted for maximum driver control and enjoyment. It's as close to a continuously variable transmission (CVT) as is possible, with discrete gear ratios. There are two automatic shift modes, Standard and Comfort, the latter of which shifts more gently and at lower engine speeds, plus is more appropriate for winter driving. Unlike with the ML350, the 2006 Mercedes-Benz E350's gearshift is controlled by a regular console-mounted shift lever.
The combination of the 3.5 V-6 and 7G-Tronic transmission makes for a first-rate driving experience. Acceleration is brisk, with 0 to 60 reported by the factory to be less than 7 seconds. With the accelerator anywhere near to the floor, the car takes off at a great rate and holds gears until redline. We couldn't find any real advantage to manual shifting. When descending grades, the transmission chooses lower gears, letting engine braking slow the car.
Only during spirited sports-type driving did manual shifting improve performance--however, not by much. At that time, too, the suspension calibration showed its true mettle. Our test car had the standard tuning of its four-link front, five-link rear suspension, not the optional sports tuning. This provided the smooth, comfortable ride expected of a luxury sedan. But when asked to perform, it did well. The steering is weighted nearly perfectly, plus it's neither too light for control nor too heavy for comfort.The 2006 Mercedes-Benz E350 has been rated by the Insurance Institute for Highway Safety as one of the safest cars on the road. As expected of a Mercedes-Benz, the 2006 E350 has a full complement of active and passive safety features. The unibody structure surrounds the passenger cabin with a strong safety cage, and front and rear crumple zones further protect occupants. Good handling, strong four-wheel antilock disc brakes with electrohydraulic operation, traction control, and the ESP electronic stability system help with active safety. In the event of an emergency, the Tele Aid system can provide assistance.
The 2006 Mercedes-Benz E350's standard 48-month/50,000-mile warranty against defects in materials or workmanship can be extended by up to an additional 36 months, with total mileage up to 100,000 miles at any time during the initial warranty period.