Expert Reviews

Test Drive: 2017 Mercedes-Benz SL550

AutoTrader SCORE
This score is awarded by our team of expert reviewers after extensive testing of the car
  • Safety

For ages, the Mercedes SL has practically owned its own market segment as one of the most popular two-seat, high-luxury drop-tops on the road. Updates and enhancements have been applied for 2017: new styling inside and out, a new nine-speed transmission, and a new entry model with V6 power.

Motivated by a 4.7L V8, twin-turbocharged for 450 hp and a hilarious 516 lb-ft of torque, available from 1,800 rpm – this torque output is about what’s required to, say, bench-press a collapsed star.

So, the 2017 Mercedes-Benz SL-Class is fresher, more modern, and more alert-looking – but it leaves core SL attributes unchanged.

Walk up, get in, get seated, and the SL’s promise of comfort-first motoring comes to the forefront. Do you like contorting yourself like a Russian gymnast, and swearing vigorously? Forget it – big door openings allow for easy step-in, with drivers dropping down into pillowy and supportive seats with adjustments aplenty. Mostly, this roadster is no more difficult to board or exit than a luxury sedan.

The cabin spreads widely around two occupants, and your 5'11" writer found no dimension lacking in space. Top-up headroom impressed, even for those over six feet tall. There’s adequate hip, knee, leg, and shoulder room, and those average in size will nearly forget that they’re sitting in a two-seater. It’s even easy to see out of by roadster standards, thanks to side windows that extend well behind the driver, and a relatively large rear window opening.

This is a gentleman’s car, and designers knew space was needed for bags and trappings and accoutrements. Within easy reach are a deep door bin, a covered center console, and two proper cupholders. Additional storage resides behind each seat, thanks to a lip-edged shelf with storage bins that run the width of the rear firewall, and are perfect for your briefcase, gym bag, camera bag, or some shopping. Just a button press slips the seats ahead in a jiff, for easy access to all of the rear storage, or the seatback-mounted document pockets, or the hanger hooks that keep classy suits upright and wrinkle-free.

If you’re a fan of a tidy and un-cluttered driving environment with a secure place for all of your things, the SL550 has you covered: I was able to travel with a lunch bag, an oversized Nalgene water bottle, a camera bag with extra lenses, a tripod, a gym bag, my phone, my wallet, and a package from the post office, all stowed neatly away, out of sight, and without even using the trunk.

Said trunk provides space for a few suitcases or overnight bags – though all items need to fit under a divider if the roof will be dropped (press the switch, take in the display of panel gymnastics, and voila!). Roof staying up on a crappy day? Lift the divider away (at a button press, of course), to increase available space by about a third.

Accessing your gear while the roof panels are stacked above it can be a dilly of a pickle in some roadsters, but it’s not a problem here: a button press lifts the panels and divider up and away, easy-peasy. Little touches, but they help the SL excel as a runabout or road-tripper that’s easy to live with, and to keep clutter-free.

Clutter could take away from the look of the cabin, after all. Instruments, interfaces, switchgear and consoles are familiar from recent Mercedes models, the whole thing enriched by a leather-stitched dash, wood trim, and the strong use of aluminum accenting. Add in the tasteful segments of color, texture and lustre, and the use of rounded edges and smooth, swoopy lines, and you’ve got an alluring and warm atmosphere that’s rife with detail. By and large, SL’s cabin fully supports its six-figure price tag.

Two key assets proved noteworthy on my test drive.

First? Ride quality.

Smooth highways see the SL float along effortlessly, as the Active Body Control suspension creates what you picture to be a virtual layer of soft, fluffy dough between the wheels and body. The system is expert at isolating drivers from rough or undulating surfaces, and sees the car float, glide and ooze along, but without feeling like a bloated, four-wheeled tarmac manatee.

On rougher in-town roads, that layer of isolation remains: you know if you’ve whacked a good crater, but the suspension does a bang-right-on job of keeping spinal abuse to an absolute minimum. It’s all carefully calibrated for the comfort-first driver, and shoppers coming from, say, an E- or S-Class will find the SL’s ride to feel familiar.

The second asset of note was the engine.

The tested SL550 was motivated by a 4.7L V8, twin-turbocharged for 450 hp and a hilarious 516 lb-ft of torque, available from 1,800 rpm. This torque output is about what’s required to, say, bench-press a collapsed star – and it makes the engine a remarkably flexible performer. A gentle throttle squeeze sends the SL sailing through traffic with revs just off idle, and little more than a subtle V8 rumble seeping into the cabin. With the new nine-speed automatic, the SL virtually idles along the highway, too.

The monster torque and whisper quiet lends itself to a feel of total ease during gentle driving. This is a world-class mill that never feels like it’s working, and it’s brimming with muscle, even if it’s happy to keep its shirt on about it.

There’s a feisty side too! Engage the Sport or Sport+ drive modes, and the suspension stiffens and recalibrates, steering tightens and heavies, and the exhaust adopts a thudding, snorty, pulsating tone that hammers away at the nearby atmosphere.

Engine and transmission sensitivities to throttle inputs increase about 879 percent, too. Here, the SL550 feels and sounds like a proper hot-rod: torque threatens to overwhelm the rear wheels, with ignition of the Continental rubber achieved easily when full throttle is applied anywhere less than about 50 km/h. The engine isn’t much for revving, but opened up, you get heavy in your seat, there’s classy thrust that borders on excessive, and the SL550 charges ahead as if a cattle-prod has been jammed into its big, sheet-metal rump. If you’re not sure whether 450 hp is enough, trust me, it is.

In its sportier modes, the car responds more quickly, urgently, and athletically to inputs, and plays ball as an entertaining driving tool with high capabilities. Notably, the steering is more crisp and direct than you think when firing the SL around sweeping bends. As a corner-carver, it’s entertaining, not exhilarating. Ultimately, this machine is less impressive as a high-precision handling weapon, and most impressive as a long-haul luxury hot-rod drop-top.

Further, two features are worth mention for effectiveness at enhancing long-haul comfort. One is the high-output LED lighting system. For all attributes of color, saturation, spread, and peripheral illumination, it’s top notch – easily top-ten by my notes. Expect confidence to spare during after-dark travels, early warning of potential roadside hazards, and for your eyes to feel comfortable and fresh, even after-hours.

Another feature works to effect similar long-haul comfort for your back. Active seat bolsters press gently into your corresponding side, in sync with the steering. This pre-emptively fixes you in your seat, as corners come and go. It feels funny and gimmicky at times, but by absorbing the subconscious workload of several dozen back muscles every time you round a bend, you’ll likely arrive where you’re going, even hours later, without any stiffness.

Complaints? The tester emitted a few buzzes and squeaks from interior panels on rougher roads, the climate control dials feel flimsy and loose, and the teensy gear selector lever, which is about the size of your big toe, takes some getting used to. It looks and feels silly, and you’ll often overreach for it, dipping your fingers into the lid of whatever beverage is in the cupholder, instead.

Further, I have 99 problems, and one of them is the SL550’s brake-pedal feel. Presumably to make things feel less nervous by way of overly touchy brakes, there’s a numb zone as application begins, and a firm, long-travel stomp is required for a fast stop. Deceleration in emergency situations is stellar, nearly startling, though the feel at the pedal is more “pickup truck” than “six-figure posh-rocket”.

All said, in several compelling ways, the Mercedes SL550 is like a luxury flagship sedan, in a luxury roadster body: it scratches the same itch for space, top-line trimmings, power, and technology to spare, with roof-off operation available at a button-press. For an investment of no less than $126,000, here’s a machine with many attributes that’ll appeal readily to the long-distance driver, or the shopper after a luxury roadster runabout that’s supremely comfortable and easy to live with on the daily.

Engine Displacement 4.7L
Engine Cylinders V8
Peak Horsepower 449 hp @ 5,250 rpm
Peak Torque 516 lb-ft @ 1,800–3,500 rpm
Fuel Economy 13.6/9.5/11.7 L/100 km city/hwy/cmb
Cargo Space 504 L
Model Tested 2017 Mercedes-Benz SL550
Base Price $126,000
A/C Tax $100
Destination Fee $2,495
Price as Tested $142,785
Optional Equipment
$14,190 – Intelligent Drive Package $2,700; Premium Package $7,300; Exclusive Package $2,800; Diamond White Metallic Paint $890; 19-inch wheel upgrade $500