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!
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.
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.
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.
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.
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.
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.
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!)