A host of electronic systems present themselves once you're underway. The blind-sport warning system lights up a triangle in the side mirrors whenever a vehicle enters the blind spot. The lane-departure warning system vibrates the steering wheel when you cross or creep toward the lane marker before activating the turn signal. The optional night-vision screen image is large, crisp and clear, and so bright and detailed at night that it can distract the driver from the task at hand.
Still, most of these new systems are less intrusive than those in many E-Class competitors. Most functions and features can be adjusted with the point-and-click dial on the center console, or with more conventional, separate switches on the dash: whichever the driver finds easier or less distracting during the process of driving. And, all the new electronic gizmos aside, the new generation models are more comfortable, more solid, quieter, and more agile than any previous E-Class.
We particularly like the diesel-powered E350 BlueTEC sedan. Mercedes' V6 turbodiesel is the smoothest, quietest diesel engine available, so virtually all the smoky, clattering drawbacks of more traditional diesel power are gone (though the oily diesel smell during fill-ups remains). Performance is virtually identical the gasoline-powered E350, with even stronger short bursts of acceleration, and the diesel engine comes with a substantial fuel mileage increase compared to nearly every other car in this class. That's good for the pocketbook, the environment and the world's geo-political balance. The BlueTEC 3.0-liter V6 turbo-diesel engine is rated 210 horsepower, 400 pound-feet of torque.
As for the E-Class gasoline engines, both the more economical 268-horsepower V6 and the more powerful 382-horsepower V8 are smooth, quiet, and responsive. Better still, Mercedes' seven-speed automatic transmission is improved compared to previous iterations. It more frequently chooses the perfect gear for the prevailing driving circumstances, and both up or down shifts come quickly. Or the driver can choose the desired gear with the steering-wheel-mounted paddles, and the transmission will stay in that gear right up to the engine's redline without upshifting automatically.
Acceleration performance is impressive, regardless of the model, and none of the E-Class variants is a lightweight. Packed with all the technology, all the luxury touches and all those airbags, an E350 sedan weighs in at 3,825 pounds and the E550 at 4,034 pounds. The 4MATIC all-wheel-drive option adds more weight. Given these figures, the spry acceleration seems even more remarkable.
E350 models are powered by a 3.5-liter V6 rated at 268 horsepower and 258 pound-feet of torque. E550 models use a 5.5-liter V8 generating 382 horsepower and 391 pound-feet of torque. The E350 V6 will sprint from 0 to 60 mph in about 6.5 seconds; the E550 V8 does the same in just 5.1 seconds, with top speed electronically limited to 130 mph.
Fuel economy is an EPA-estimated 17/24 miles per gallon for the E350 sedan. The E350 coupe rates 17/26 mpg, E350 cabriolet gets 17/25 mpg, E350 4MATIC sedan rates 17/24 mpg, E350 4MATIC wagon gets 16/23 mpg. The E350 BlueTEC is rated 22/33 mpg. The E550 sedan, 4MATIC sedan and coupe are rated 15/23 mpg, the E550 cabriolet is rated 15/22 mpg. The E63 AMG is rated 13/20 mpg.
There's a nice balance of comfortable ride and good handling response, even in the standard models, which put a bit more emphasis on the ride. All E-Class variants have a variable damping system that changes the rebound rate of the shock absorbers according to conditions. This allows a softer, quieter ride on smoother roads, but retains full shock damping through dips, or for spirited driving on twisting two-lanes.
The E-Class brakes are world-class, with the latest electronic controls and built-in automatic braking with the Distronic radar-controlled cruise option. These brakes are consistently powerful at the wheels, progressive and reassuring at the pedal, and they always come back, no matter how hot they may get in a spirited drive.
The E-Class Cabriolet is loaded with features intended to extend open motoring throughout the year. One is AIRSCARF, which uses neck-level heating vents under the headrests. Another is a new device called AIRCAP: an aerodynamic deflector mounted at the top of the windshield.
AIRCAP contains 211 separate parts with 70 patents, and it can be raised roughly 2.5 inches at the driver's discretion to redirect airflow over the top of the E-Class Cabriolet's open cabin. The point? AIRCAP virtually eliminates buffeting (not to mention wind noise) for front-seat passengers when the convertible top is lowered. It reduces buffeting for rear-seat passengers to levels comparable to that experienced by front-seat passengers in other four-place convertibles, according to Mercedes. And it does so without the drawbacks associated with more familiar, screen-type wind blockers raised behind the front seats: reduced visibility, and elimination of rear-seat passenger space. There's at least a slight payback with AIRCAP, to be sure. When the airfoil is raised, the E-Class Cabriolet's roof-open drag coefficient rises from 0.33 to 0.38, and that could have a measurable effect on fuel economy. Nonetheless, AIRCAP works as billed, and allows the quietest, buffeting-free open motoring we've experienced.
We found the E550 accelerates like a rocket with the silky V8 and improved 7-speed transmission (we got 18 mpg average), and handles more precisely than any E-class we've known. The suspension in the E500 Cabriolet we drove might be too firm for some, though; over patchy freeway roads you can feel the jolts, as if the car is trying to defeat the bumps rather than absorb them.