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2013 Mercedes-Benz SL550 Convertible review: 2013 Mercedes-Benz SL550 Convertible

We drop the top and hop behind the wheel of a bright-red status symbol, and find it to be big on style but not on tech.

Antuan Goodwin Reviews Editor / Cars
Antuan Goodwin gained his automotive knowledge the old fashioned way, by turning wrenches in a driveway and picking up speeding tickets. From drivetrain tech and electrification to car audio installs and cabin tech, if it's on wheels, Antuan is knowledgeable.
Expertise Reviewing cars and car technology since 2008 focusing on electrification, driver assistance and infotainment Credentials
  • North American Car, Truck and SUV of the Year (NACTOY) Awards Juror
Antuan Goodwin
15 min read

The SL is the sort of vehicle that swivels heads and elicits comments like only a bright red Mercedes-Benz convertible can. Everyone wanted to take a closer look. Even my most car-averse friends couldn't keep their hands off of the paint and I was taken aback when a normally conservative young lady described the Mars Red SL550 Roadster as "sex on wheels." Oh, my!

2013 Mercedes-Benz SL550 Convertible

2013 Mercedes-Benz SL550 Convertible

The Good

The <b>2013 Mercedes-Benz SL550</b>'s V-8 Biturbo engine is powerful and smooth. Motoring with the top down is amazingly quiet and comfortable. A full array of media sources and a premium audio system are standard features.

The Bad

Comand Online is almost unusably slow in its operation. The physical controller-based infotainment system takes a while to learn. Fuel economy is, predictably, low.

The Bottom Line

The 2013 Mercedes-Benz SL550 Roadster is an excellent luxury convertible that doesn't rely heavily on tech gimmickry; however, its new Comand Online system falls short of the bar set by Audi and BMW.

Raunchy comments aside, the SL550 Roadster features classic sports-car proportions. Its long nose starts with an almost comically large Mercedes-Benz tristar badge flanked by large HID headlamps with LED accents and flows over the optional 19-inch AMG five-spoke wheels. Massive hood vents just before the steeply raked windshield had observers asking me if this was the SL63 AMG, to which I snobbishly replied, "No, it's only the SL550." The passenger compartment seats two under its low-slung, abbreviated roof line. Just behind the cockpit is an abbreviated, rounded rear deck.

Comfortable convertible
Being a Roadster, the two-seater SL features a convertible top. And being a Mercedes-Benz, that convertible top is a power-retractable hard number that lowers in a fit of robotic ballet in about 6 seconds. Top-down storage space is limited by a cover that prevents the cargo from interfering with the operation of the roof, but there's still space for a pair of carry-on bags and a few odds and ends beneath the power-lift and closed trunklid. With the top up, that cover can be shifted out of the way to increase storage space, but you won't be able to drop the top until it is replaced. Even getting into the trunk with the top down is a dramatic affair, requiring that the trunklid lift and then the folded roof and rear glass panels be automatically lifted out of the way. Finally, the storage compartment cover must be lifted, manually, out of the way before you're given access to the trunk. That's a lot of moving parts just to toss your gym bag in the boot, but these steps are necessary for that increased top-up cargo space.

SL550 trunk

The SL has a reasonable amount of trunk space, even with the top down.

Josh Miller/CNET

The SL's cabin is anything but cramped, with more than enough space for two very tall adults. Seat adjustments are motorized, as is the steering-wheel adjustment, with three memory positions and an Easy Exit mode that automatically slides the seat back and retracts and lifts the steering wheel when you open the door of the stopped Roadster.

A small parcel shelf and a pair of storage compartments accomodate any man bags, purses, or other odds and ends that you don't want flying away when the top drops. This is a trivial nitpick, but the cupholders are located so far back on the center console that this car might as well not even have them. I'd recommend a "No drinking in the Benz" rule, but I may just be overprotective of this $105,500 toy.

The SL Roadster comes packed with a number of features that make open-air motoring a pleasant experience, even during one of San Francisco's chilly, foggy mornings. A motorized windscreen can be raised to reduce buffeting at freeway speeds; Mercedes' Air Scarf system blows warm air onto the passengers' necks from the headrests to cut the chill; the automatic climate controls adjust automatically for top-down motoring; and heated and ventilated seating surfaces gently warm or cool your bottom and back. With the side windows and windscreen up and the Air Scarf and heated seats keeping me toasty, there's no situation short of snow or rain that could convince me not to take a moment and drop the top. Wind noise is so low that I was able to have a conversation with my passenger or make a hands-free call without shouting. Factor in four-level seat massage motors and driving the SL550 with the adaptive cruise control set to 85 mph is downright relaxing. Hopefully, not so relaxing that you doze off, or the Attention Assist drowsiness detection system will start beeping at you.

massage seat screen

Massage seats with active bolsters soothe passengers during long trips.

Josh Miller/CNET

Of course, there may be a time when you have to raise the top and treat the SL like a coupe. With the top up, the SL goes from remarkably quiet for a Roadster to silent as a tomb. However, that doesn't mean that you shouldn't still be able to enjoy the sky, which is where the optional (and ridiculously named) Mercedes-Benz Magic Sky Control comes in. This $2,500 transparent glass roof panel blocks UV and IR light from entering the cabin while still letting visible light in. However, at the touch of a button, the glass can be made almost completely opaque, shading the driver and passenger from the sun. It's pretty amazing and drew many oohs and ahhs from passengers. If you've ever seen an automatically dimming rearview mirror, you already have a pretty good idea of how this "tint on demand" system works on a much smaller scale.

Performance and handling
Under the SL's hood hums a 4.6-liter V-8 biturbo engine that's as much a work of art as the chassis. Direct-injection technology, a defeatable autostop feature, and an Econ shift program on the seven-speed automatic transmission help this mill to average 16 mpg in the city, 24 mpg on the highway, and 19 mpg according to EPA's combined calculations. These aren't great numbers compared with your average passenger car, but from a machine that makes 429 horsepower and 516 pound-feet of torque, I'll take what I can get.

engine bay

The Mercedes-Benz SL550 is all about excess. Its 4.6-liter biturbo engine is no exception.

Josh Miller/CNET

I'm sure that the stock SL550 Roadster's suspension tune makes it a fantastic handler, but I can't confirm it, because our tester was equipped with the optional $4,090 Active Body Control (ABC) adaptive-suspension package. Like most adaptive-suspension packages, ABC features two modes (Sport and Comfort), but it does quite a bit more. At the tap of a button, the SL can be raised about 2 inches to clear speed bumps and other obstructions at low speeds. As the speed increases, ABC also lowers the vehicle below the static ride height (maxing out at about 0.5 inch at about 80 mph) to reduce wind resistance for better fuel economy and reduced noise and lower the center of gravity for better high-speed stability. While all of this is happening, the four dampers at the corners of the vehicle are constantly adjusting to provide the best responsiveness or comfort. You can watch all of this ride height adjustment and damper tweaking happening on the Comand system's color display alongside a two-axis G-force meter, but I'd recommend that you instead keep those eyes up and ahead.

Around town and on the highway in its most comfortable transmission and ABC setting, the SL550 is probably best described as "effortless." It's got more power than it needs for sliding between stop lights, so it can keep its revs low and gearing tall without compromising responsiveness. With the minimal throttle inputs required to reach and maintain the city-average 35 mph speed limit, the Benz is quiet and smooth. While ABC can't completely obliterate the bumps of San Francisco's lunar downtown street surfaces, it does manage to take most of the harshness out of the bumps, which is good.

The autostop system would shut down the engine at stop signs and traffic lights once the engine had been sufficiently warmed up. I didn't find the system to be tremendously intrusive during those moments when I was coming to a complete stop, such as at an intersection. However, when it started kicking in during stop-and-go traffic, I was glad that the button to defeat this function was readily available on the center console.


Controls for the seven-speed gear box and Active Body Control are located on the center console.

Josh Miller/CNET

On the highway, the ride is equally smooth and quiet. However, the Econ shift program is hesitant to drop down a gear for passing maneuvers. I often had to wait a few beats for the gearbox to go, "Oh, I see!" and give the downshift that I was requesting. However, usually by then I'd have dialed in a bit more throttle than I needed, which resulted in the car lurching forward suddenly faster than I'd originally intended.

Selecting the Sport shift program and the Sport ABC mode, the SL550 comes alive. Lower gears are held slightly longer and downshifts are easier to request and predict with the accelerator pedal, sacrificing a few mpgs to have all 429 thoroughbreds on tap when you need them. The chassis also felt more responsive to steering input, although the adaptive nature of the system still soaked up much of the harshness of the road. Unless you're rounding a bend, you probably won't notice much difference between Sport and Comfort modes, so I elected to just leave it in Sport for much of my testing.

The SL550 also features a manual shift mode actuated by steering-wheel paddles, but I found timing the shifts of the conventional manual transmission tricky and elected to let the Sport program do the thinking for me.

Active bolsters on the seats can be set to inflate to hold the driver and passenger in place during cornering. I found this system to be annoying at anything less than eight-tenths of where I estimate the Benz' capabilities lay and left it either off or at its lowest setting most of the time.


Nineteen-inch AMG wheels filled with performance brakes are part of a $2,000 option package.

Josh Miller/CNET

An open, twisty road in California's wine country is truly this car's natural environment, not the autobahn or under the gray skies of the Nurburgring's Nordschleife. (Having never been to either, this is pure speculation, of course.) The almost Mediterranean climate and flowing B-roads seem to perfectly match the SL550 Roadster's suspension tune, overconfident power train, and brash aesthetic. I found it easy to settle into a groove with the vehicle as I tossed it through S-curves, making my way from the country to the coast.

Stability control was unobtrusive and never intervened during my testing, so I mostly left it on. The sole exception was when I switched it off to do a few doughnuts in an empty parking lot, dancing the Roadster around its center axis in a puff of tire smoke. (The SL550 may be a classy ride, but I still revert to a 16-year-old whenever I'm left alone for too long with 500+ pound-feet of torque!)

Dashboard technology and Comand Online
So far, I've had nothing but praise for the SL550 Roadster -- all of which is well-deserved, this is an impressive ride. However, things start to fall a bit flat in the cabin where the tech is concerned. Now I assume that the sort of person who buys a status symbol that starts above the $100K mark doesn't care about such things, but infotainment, particularly the new Comand Online feature, is the SL's Achilles' heel.

At its core, the SL's infotainment system is based on Mercedes-Benz' Comand interface, utilizing the now familiar console-mounted Comand control dial and a three-level Comand onscreen interface. The thing is that even though it's been around for almost a decade, I find that Comand is a challenge to get the hang of again every time I settle behind the wheel of a Benz. There's just too much dial-twisting, list-scrolling, and button-pushing to access basic features like switching audio sources or changing the map mode. The problem is that Mercedes-Benz has been constantly adding features to Comand, but hasn't really rethought the way it organizes all of that new information, which leads to the bloated and poorly organized system that we see in today's SL. We'll come back this shortly.

COMAND interface

The Comand system should be familiar by now, but it suffers from feature bloat and poor organization.

Josh Miller/CNET

Fortunately, there's a voice entry screen with above-average accuracy to rescue you from the hell of inputting a street address using the Comand controller. Drivers should take advantage of this system at every opportunity. I only wish there were more ways to use voice input for some of the more advanced features offered in this dashboard.

Comand provides navigation with traffic data. The map is crisply rendered, but (despite Comand being equipped with a data connection) lacks any sort of topographic or Google satellite imagery.

Audio sources include a six-disc DVD changer with MP3 and DVD-Audio playback, an iPod/MP3 media interface with a 30-pin dock connector and a USB connection in the center console, an SD card interface on the dashboard for audio playback, SiriusXM Satellite Radio, a chunk of the navigation system's hard drive dedicated to audio ripping and storage, and terrestrial AM/FM tuning with HD Radio decoding. Bluetooth hands-free calling with address book sync and Bluetooth A2DP audio streaming round out the SL550's standard audio sources that feed the standard Harman Kardon Logic7 5.1 surround-sound system. This audio rig features a nice feature called FrontBass that adds two 8.5-inch speakers mounted ahead of the driving position to create what Mercedes calls "a concert hall ambiance in a roadster." I think that's a bit hyperbolic, but the system does sound great.

Drivers who truly want that "concert hall ambiance" can elect to drop the extra dough on the optional 900-watt, 12-speaker Bang & Olufsen uberpremium audio system, which bests the Harman Kardon system by 300 watts, with two additional speakers, and with higher-quality components. It's also an additional $6,400 over the already premium Harman system.

The SL is one of the first new Mercedes-Benz vehicles to feature the new Comand Online connectivity suite, which includes an always-on data connection and a host of new Web-connected services such as Google Local Search, News, Yelp search, and Facebook. Unfortunately, here is where things really go wrong for Comand.

comand onlin

The new Comand Online system is the weak link in the Benz' dashboard experience.

Josh Miller/CNET

The main problem with Comand Online is that it is agonizingly slow. Just getting from the main Comand interface to the Comand Online home screen takes you through a 30-second load screen. Popping into any of the submenus takes an additional 5 to 10 seconds, which means that getting from the main map screen to the point where you can actually input a Google Search term can take over a minute, which is forever in car time and an eternity in consumer tech time. The fact that the system (rightly) locks you out of most of Comand Online's major functions when the vehicle is in motion means that in most cases it's faster to just whip out your smartphone to make that Facebook status update.

If you don't mind waiting (and are the only person reading CNET who doesn't have a smartphone), Comand Online lets you, first, use Google Search to find points of interest near a location. You can input search terms or select from a list of the most popular or your most recent search terms. Once the destination is selected from the list of results, you can call the location using the hands-free system, set the location as a destiation for navigation, add the location to your address book, or view a 360-degree Google Street View or collection of nearby Panoramio photos. It's slow, but Google search is useful.

Also useful is the Yelp integration, which gives another way to search for nearby businesses. However, I did run into a bit of weirdness here as well. Now, I'm not sure how the Yelp search algorithm works, but a search in the area of Oakland, Calif., for the popular and highly rated Zachary's Chicago Pizza yielded no results that matched the search term. While most of the results were for pizza places, the algorithm seems to place proximity to the Oakland city center at a higher importance than matching the search term to the title. After five pages of scrolling, I noticed that one of the results was for a popular Oakland bakery called Bakesale Betty, which is definitely not a pizza place, and decided to give up and just grab one of Betty's famous chicken sandwiches instead. For every Yelp entry found, I was able to view an average Yelp rating on a scale of 1 to 5 stars, see the total number of reviews submitted, read the most recent three reviews posted, view a photo or a Google Street View view, call the location using hands-free calling, or import the destination into the Benz' main address book.

The news app seemed to be the least useful portion of Comand Online system. From here, I could select from a number of news categories to view the latest headlines and read the top news stories on the SL's color screen. There didn't appear to be any sort of text-to-speech option to have the stories read aloud while I drove, but I was given the option to have any of those stories e-mailed to a preselected e-mail address for later reading.

Facebook in the dash

Facebook integration is broad, but hindered by ridiculously slow performance.

Antuan Goodwin/CNET

Facebook integration is the most ambitious part of Comand Online, but also the bit that's most plagued by slow load times. From the Facebook menu, I was able to view nearby locations and check in, find locations that friends had checked into, view my news feed of friends' subscribed status updates and Like those that interested me, view nearby events that I'd RSVP'd to and navigate there, update my own status, and view the Mercedes-Benz Facebook fan page. The status update function allows users to choose from a few canned messages, such as "I'm currently stuck in traffic near [current location]," but there is the option to input a custom message using the Comand controller while the vehicle is stopped. Take my advice and just don't bother. I was able to input "I'm updating my status with the COMAND system in the Mercedes-Benz SL550. Don't worry, the car is p" before I reached the 100-character cap, and just those few words took about 5 to 7 minutes to input.

One particularly frustrating element of Comand Online is the inconsistent behavior of the Comand controller's back button compared with the rest of the Comand interface. On any other screen, the back button takes you backward one step in your current menu, but when online, the back button takes you all of the way back to the Comand Online home screen. For example, if you're viewing a friend's Facebook status update and tap the back button on the Comand controller (rather then selecting the virtual back button on the screen), you'll be kicked all the way back to the main menu, which means that you have to navigate through the menus again (and wait through all of the loading screens again) to get back to the list of Facebook statuses. This may seem like a nitpicky thing, but it makes the entire interface more difficult to deal with. After one too many accidental taps of the back button, out came my smartphone, which was infinitely better suited for social networking and searching while parked.

Similar app integration and connected services from the likes of Audi and BMW are noticeably faster and more inviting experiences than Comand Online. I also dislike that Mercedes' connected services seem to be sequestered from the rest of the entertainment experience. You gain no observable benefit in the form of more accurate traffic on the map screen or satellite imagery. You have to leave the navigation system and explicitly enter the Comand Online system to search for a destination. As a result I think most users will probably forget that it there after the first couple of weeks, especially because it's such a frustrating endeavor to use.

SL550 parked

Fortunately, the issues with the technology paled in comparison with the rest of the SL driving experience.

Antuan Goodwin/CNET

In sum
The SL550 is a brilliant automobile. Sure, Comand Online is a train wreck, but it doesn't ruin the vehicle that Mercedes' chassis and engine engineers and designers have built around it. There's just so much to like about being behind the wheel of a big, red Benz that I find myself over 3,000 words into this review and I haven't even touched on the safety features such as the Mbrace telematics system, the lane-keep assistance system, the precollision warning system, the blind-spot monitoring, and the rearview camera with proximity detection and Parktronic parking assistance. If they never venture into the Comand Online menu, I think most owners will be pleased with their SL550 Roadster purchase -- at least until they see someone valeting an SL63 AMG.

Our 2013 model started at $105,500 before adding $900 for its premium leather interior. Illuminated door sills and an analog clock on the dashboard are take-it-or-leave-it options that add $350 and $250 to the bottom line, respectively. The Magic Sky Control glass roof is a nice party trick that will cost you $2,500, but if you're like me, you'll be spending too much time with the top down to really take advantage of it. The easy-as-ABC adaptive suspension is a $4,090 option, and a $4,900 Premium package adds Air Scarf, cooled seats, massage seats, keyless entry, and the rearview camera/proximity detection system that will keep you from scuffing the SL's pretty red paint. Blind-spot monitoring and precollision detection are part of a $2,950 Driver Assistance package and an additional $2,000 gets you the 19-inch AMG wheels with stickier tires and a host of go-faster and look-faster bits. Toss in a $905 destination charge to reach our as-tested price of $124,345.

That's a pretty penny -- certainly too rich for my blood -- but cars like the SL550 Roadster are all about a feeling, not a value, and this Roadster feels like it's worth it.

Tech specs
Model2013 Mercedes-Benz SL550 Roadster
Power train4.6-liter biturbo V-8, RWD, 7-speed automatic transmission
EPA fuel economy16 city, 24 highway, 19 combined mpg
Observed fuel economyn/a
NavigationStandard, HDD-based
Bluetooth phone supportStandard
Disc player6-disc DVD changer
MP3 player supportStandard analog 3.5mm auxiliary input, USB connection, Bluetooth audio streaming, iPod connection
Other digital audioSiriusXM Satellite Radio, HD Radio
Audio system10-speaker, 600-watt Harman Kardon Logic7 5.1 surround with FrontBass
Driver aidsRear camera, proximity detection (4 corners), blind-spot monitoring, lane keep assistant, adaptive cruise control, precollision warning, Attention Assist driver alertness monitoring
Base price$105,500
Price as tested$124,345
2013 Mercedes-Benz SL550 Convertible

2013 Mercedes-Benz SL550 Convertible

Score Breakdown

Cabin tech 7Performance tech 8Design 9


See full specs Trim levels SL550Available Engine GasBody style Convertible