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The speedometer display also showed a graphic of distance to other cars ahead of us, as our E550 Cabriolet came equipped with Mercedes-Benz's adaptive cruise control. This very convenient system lets you set a cruising speed, then uses forward-looking radar to detect slower-moving cars ahead, matching your speed to theirs. With the system activated, we were impressed that it could bring the car to a complete stop, and let us choose from three following distances.
Radar from the system is also used for Mercedes-Benz's Pre-Safe technology, which automatically tensions the seatbelts and hits the brakes if it thinks a collision is imminent. Pre-Safe seemed a little touchy to us, as it occasionally gave its initial warning and seatbelt tensioning as we drove with a row of parked cars on the outside of a turn, or went from the dark shade of an underpass to bright sunlight. But during these false alerts it did not go into its braking stage.
As its name suggests, the E550 Cabriolet's engine is a 5.5-liter V-8, which Mercedes-Benz introduced with its S550 in 2006. With 382 horsepower and 391 pound-feet of torque, the E550 steps off the line fast enough to threaten its rear-wheel grip. During our fast starts, it felt like Mercedes-Benz tuned the car to the very edge of where the tires would break loose.
The E-class is also available as the E350 Cabriolet, using a 3.5-liter V-6. In other Mercedes-Benz models we've tested, this engine felt a little poky. The V-8 is certainly more satisfying, but it also sucks down the gas. EPA ratings for the car are 15 mpg city and 22 mpg highway. We never saw the trip meter go above 20 mpg, even with a long freeway trip thrown in, and ended up with an overall average of 18.4 mpg.
This V-8 doesn't push the efficiency envelope, lacking technologies such as direct injection or turbocharging. The power train's saving grace is its seven-speed automatic transmission, with gears tall enough to let the engine run under 2,000rpm even when the car's speed is 75 mph.
The transmission includes both standard Drive and Manual modes, with paddle shifters for manual gear changes. Although not terribly snappy, the transmission shifted reasonably fast when we pulled the paddles. An M button near the shifter puts the transmission into Manual mode, where it seemed happy to let us get the engine speed up toward redline.
The E550 Cabriolet also had a Sport button on the center stack, somewhat lost among buttons for seat cooling and heating. When engaged, this Sport mode sharpened the throttle response, giving the car a touchy, thoroughbred feel, with minor throttle input yielding big results.
The suspension is conventional, and tuned more for sport performance than luxury. We liked how well it kept the car hunkered down in turns, the steering wheel responding with a very precise feeling. And in particular, we noted the car's willingness to let its hair down when pushed in the turns, the back end feeling loose and ready to party. Where BMW's allow an amount of rear slip you can practically measure, the E550 Cabriolet seemed less constrained.
Some of that playfulness may have been because of the 18-inch AMG wheels, fitted with all-season performance tires, which came with the car as part of an Appearance package. These wheels might have also affected the ride quality, which was just a little harsher than we would expect from a Mercedes-Benz. We wouldn't call the ride rough, but there is a sports car rigidity apparent.
In more sedate driving, running errands in an urban environment, for example, we were pleased to find a tight turning radius with the car, allowing easy parking lot maneuvering and U-turns on streets.
It's hard not to like a convertible, and the 2011 Mercedes-Benz E550 Cabriolet has a lot to offer beyond open-top driving. Mercedes-Benz did a good job on external styling, always a challenge when replacing the top of a car with cloth. But the squashed trunk space removes some of the practicality, and though we have gotten used to the cabin tech interface, the design is somewhat quirky.
The car offers a taut driving feel, achieving sports car handling beyond Mercedes-Benz's past efforts. But in these days of direct injection and turbocharging to heighten fuel economy, the engine seems a little basic. The seven-speed transmission is a tech win.
Mercedes-Benz's cabin tech has some excellent qualities, but it does not push any boundaries. Lacking are any external data sources besides traffic, such as weather or fuel prices. High points include the Harman Kardon audio system and the adaptive cruise control, one of the best in the business. Cell phone and MP3 player connectivity is no better than in cars costing substantially less.
|Model||2011 Mercedes-Benz E-class|
|Power train||5.5-liter V-8, seven-speed automatic transmission|
|EPA fuel economy||15 mpg/22 mpg|
|Observed fuel economy||18.4 mpg|
|Navigation||Hard-drive-based with traffic|
|Bluetooth phone support||Standard with contact list import, dial by name|
|Disc player||MP3- and video-compatible six-disc changer|
|MP3 player support||iPod integration|
|Other digital audio||Onboard music library, PC Card, satellite radio, HD Radio, auxiliary input|
|Audio system||Harman Kardon 12-speaker 450-watt Dolby Digital 5.1 system|
|Driver aids||Adaptive cruise control, rearview camera, park distance warning|
|Price as tested||$77,425|