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2017 Mercedes-Benz S-Class review: Ultimate comfort, even in a traffic jam

With unparalleled ride comfort and sophisticated adaptive cruise control, the S550 Cabriolet delivers a stress-free experience even in the worst traffic.

Wayne Cunningham Managing Editor / Roadshow
Wayne Cunningham reviews cars and writes about automotive technology for CNET's Roadshow. Prior to the automotive beat, he covered spyware, Web building technologies, and computer hardware. He began covering technology and the Web in 1994 as an editor of The Net magazine.
Wayne Cunningham
6 min read

After a month spent flying back and forth to Los Angeles, my boarding passes a confused jumble in my Apple Wallet app, I finally broke free enough time to drive down from San Francisco. The occasion was the Los Angeles auto show, and my ride would be a 2017 Mercedes-Benz S550 Cabriolet.

8.4

2017 Mercedes-Benz S-Class

The Good

Like its S-Class compatriots, the 2017 Mercedes-Benz S550 Cabriolet stands out for its exceptional ride comfort. Sophisticated adaptive cruise control handles braking and acceleration even in stop-and-go traffic, and its Burmester stereo delivers detailed music.

The Bad

Mercedes-Benz badly needs to redesign the S550 Cabriolet's dashboard electronics from the ground up, as the interface has become a complicated mess. A problem with many convertibles, trunk room becomes very limited with the top down.

The Bottom Line

The 2017 S550 Cabriolet maintains the strengths of Mercedes-Benz S-Class vehicles, showing off a luxury exemplified in driving character and cabin appointments, while offering top-down driving rarely found in its segment.

Cruising down a California highway, over valleys, mountains and coastal terrain, compared to stuffing myself into an airline seat, shoulder-to-shoulder with some rando? I will take the former any chance I can.

And the S550 Cabriolet made the perfect vehicle for the trip, as it fit right in cruising top-down through Beverly Hills, or drifting over hundreds of freeway miles. Massaging seats eased the strain on my back, the Burmester stereo filled the quiet cabin with pristinely produced music, and adaptive cruise control handled the trials of stop-and-go traffic.

Most of all, though, the S550 Cabriolet, and all the S-Class variants, delivers what I consider the best ride quality of any car on the road today, even the ultraluxury models.

2017 Mercedes-Benz S550 Cabriolet

Mercedes-Benz previously delivered sedan and coupe versions of its flagship S-class, and now adds the drop-top Cabriolet.

Josh Miller/CNET

Mercedes-Benz gave its S-Class sedan a major update for the 2014 model year, in almost every way delivering a vehicle worthy of the brand's luxury reputation. Following the sedan came an S-Class beautifully styled coupe and now the Cabriolet, the convertible version. To be honest, I prefer a hard top, and like the look of the coupe better, but the Cabriolet certainly earns points for its top-down demeanor. Like the coupe, the S550 Cabriolet gets by with two doors but also room for four passengers.

The comfort

The S550 Cabriolet's unparalleled ride quality made me look forward to spending hours driving it down the coast, but the plush look of its cabin got my attention when I first opened the door. Prominently displayed Designo labels announce the Mercedes-Benz's upscale interior brand, while ventilated leather in Porcelain, or white if you prefer, cover the substantial seats.

Door-mounted controls made it easy to adjust everything from headrest height to thigh-rest length. Climate control, helped by heated and cooled seats along with warm air vents in the headrests, made cruising with the top down perfectly comfortable through a wide temperature range. The seats offered a variety of massage types, including one that made use of the seat heaters to really loosen my muscles.

Sun times in the 2017 Mercedes-Benz S550 Cabriolet

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Although the S550 Cabriolet uses a fabric top, I could see there was more than just a simple sheet of canvas between me and the sky. Extra padding ensures rigidity against buffeting and does an extraordinary job limiting noise. Likewise, double-pane side windows keep the cabin serene.

Most of all, though, Mercedes-Benz's Airmatic suspension does wonders absorbing the pounding produced by rough pavement and potholes. Like its name suggests, the suspension uses air-filled struts instead of steel springs, and continuously adjusts the air pressure to compensate for the road. It does a remarkable job of creating a smooth ride while at the same time avoiding excessive wallow. At the push of a button I could switch between Comfort and Sport modes, the latter stiffening up the ride a little yet never becoming hard.

On the road for hundreds of miles, I rarely felt a need to stretch my legs, to the point where the car's own safety systems flashed a suggestion on the instrument cluster that maybe I should take a break.

2017 Mercedes-Benz S550 Cabriolet

The cabin of the S550 Cabriolet offers a high degree of comfort, complete with massaging seats and warm air blowing from the headrests.

Josh Miller/CNET

The drive

Complementing the very, very comfortable ride, the S550 Cabriolet's throttle and steering worked with a buttery ease. 4.7 liters of turbocharged V8 may sound like an ingredient for a modern muscle car, but this convertible doles out its 449 horsepower like a cake boss applying frosting. Give the throttle a little tip-in, and the car responds precisely. Its 516 pound-feet of torque leads to stately acceleration, and it recovers from its fuel-saving idle stop feature without hesitation.

When I stamped down on the accelerator to get all that power at once, the big V8 growled in accompaniment to the car's leap forward. Making a pass on a two-lane highway, I quickly found myself approaching triple digit speeds.

2017 Mercedes-Benz S550 Cabriolet

AMG versions of the S550 Cabriolet come with more powerful engines, but this twin-turbocharged 4.7-liter V8 should be enough for most people.

Josh Miller/CNET

The S550 Cabriolet's spec sheet tells me its transmission houses nine gears, but I rarely felt them. This transmission is a smooth operator, until I put it in Sport mode where it locked out the top three gears. Cruising on the freeway, the virtual tachometer on the car's wide instrument cluster LCD panel hung around 1,300 rpm, whether I was on a straight or climbing a hill.

The result of the nine-speed transmission and fuel-saving features such as idle stop is an EPA-rated fuel economy of 17 mpg city and 25 mpg highway. I found those numbers believable as I averaged over 23 mpg, combining fast freeway travel, city cruising and plenty of stop-and-go traffic. At the S550 Cabriolet's $131,400 base price, buyers may not be terribly concerned about fuel economy, but consider that, with the car's 21.1 gallon tank, I only stopped twice for gas on my 900-mile trip.

The traffic

Los Angeles traffic enjoys a notorious reputation, but the Bay Area holds its own in this regard, and I got to experience the 5 p.m. hellishness of both. Entering LA on a Monday afternoon, the S550 Cabriolet's navigation, a standard feature, went hyperactive, changing the route every 15 minutes to try to avoid traffic. It might have been more effective if it included the ability to route on to HOV lanes, as the addition of my photographer in the car put us over the two-person threshold.

Navigation did little to help me cope with traffic, but the S550 Cabriolet's driver assists proved a godsend. In stop-and-go traffic on a long freeway stretch approaching San Francisco, I set the adaptive cruise control, turned off the angry red traffic display on the dash, and enjoyed the detailed music reproduction from the 13-speaker, 590-watt Burmester stereo system.

When traffic slowed to 5 mph or came to a complete stop, the S550 Cabriolet tucked in close enough to the car ahead to prevent opportunists from cutting in, widening that gap when speeds resumed. I literally did not touch the brake or gas pedal for miles and miles of slow traffic, even as it accordioned between a crawl and occasional jumps to 60 mph. Lane-keeping assist also served to take over steering when the pace dropped below about 15 mph. If this is our driverless car future, sign me up.

The screens

As with other recent Mercedes-Benz models, the S550 Cabriolet sports two wide LCD panels, one for the instrument cluster and one for infotainment. The virtual gauges look realistic, and with the night vision option, I could get an infrared view of the road ahead at the touch of a button, a nice safety feature to help avoid running over The Rock's French bulldog as he walks it along dark Beverly Hills streets.

2017 Mercedes-Benz S550 Cabriolet

Two wide LCD panels make up the S550 Cabriolet's instrument cluster and infotainment display.

Josh Miller/CNET

On the infotainment side, Mercedes-Benz offers the usual navigation, stereo interface, Bluetooth phone system and connected features, supported by a data connection into the car. However, the interface needs a major revamp, as it includes legacy drop-down menus kludged together with newer icon-based menus. It's kind of a mess, and not really up to the standards of such a tech-forward company.

And lacking support for Android Auto or Apple CarPlay, I could not escape into my familiar phone interface.

2017 Mercedes-Benz S550 Cabriolet

The mechanism for the drop top compromises luggage room somewhat, limiting it to two rollies and a backpack or two.

Josh Miller/CNET

The competition

Not many automakers offer big, luxury convertibles, leaving the 2017 Mercedes-Benz S550 Cabriolet in a rarefied space. For quite a few bucks more, Bentley offers its Continental with a cloth drop top, but the dashboard electronics and ride comfort are inferior to the S550 Cabriolet. A more challenging competitor comes from BMW in the form of the 6 Series convertible, trading pure comfort for athleticism, while offering better dashboard electronics at a significantly lower price.

The S550 Cabriolet owns its segment for coddling passengers, but it also suffers from a typical convertible problem. Put the top down, and trunk space becomes severely compromised. And with limited rear seat room, the S550 Cabriolet only practically shares its comfort with two people at a time. And that makes it even more perfect for those who don't like crowds.

8.4

2017 Mercedes-Benz S-Class

Score Breakdown

Performance 9Features 9Design 8.5Media 6.5