Used 2015 Mercedes-Benz SL-Class SL 400 Convertible Review

For 2015, Mercedes' SL lineup adds a new, more affordable V6-powered SL400 model. On the audio front, the standard Harman Kardon system drops to 11 speakers instead of 14, and the six-disc CD changer has been dropped. The SL AMG model's Performance package has also been eliminated, but its limited-slip rear differential, power boost and top speed increase are now standard.

Though its styling may be an acquired taste, the 2015 Mercedes-Benz SL-Class roadster provides a beautifully executed blend of luxury, technology and performance.

You simply can't drive a 2015 Mercedes-Benz SL-Class without being amazed by both the depth and breadth of its skill set. The SL's slick three-piece retractable hardtop offers both the comfort and security of a coupe and the wind-in-your-hair motoring experience of a convertible. Four different engines are available, giving you a range of horsepower from 329 to 621. Then there's the exquisitely detailed cabin and long list of standard features and options. In pretty much every respect, this is a spell-bindingly excellent car.

The biggest news in the SL-Class lineup this year is the introduction of the new SL400 variant that has a V6 engine under that rather prominent hood. A V6? Blasphemy! But with still-respectable acceleration and an as-new MSRP $20,000 below its siblings' six-figure price tags, this new entry-level model promises to open up the possibility of SL ownership to more buyers than ever before. For those with more substantial budgets and more aggressive driving habits, of course, the SL550, and high-performance SL AMG and SL 65 AMG models return largely unchanged.

Expectedly, this elite luxury roadster realm is filled with appealing alternatives. If you want something with sportier handling, the 2015 Audi R8, 2015 Jaguar F-Type and 2015 Porsche 911 would all be better choices. And at the price of the SL 65 AMG, perhaps you'd find the exotic 2015 Bentley Continental GT more appealing. But overall we think it's a very good thing to be an SL driver, and Mercedes' iconic luxury roadster has arguably never been more appealing.

The 2015 Mercedes-Benz SL-Class is a two-seat, retractable-hardtop convertible that's now offered in four trims: SL400, SL550, SL AMG and SL 65 AMG.

The new entry-level SL400's list of standard features includes 18-inch wheels, an adaptive suspension, adaptive xenon headlights, automatic high-beam control, front and rear foglights, LED daytime running lights, automatic wipers and a see-through power-folding hardtop. Inside you'll find dual-zone automatic climate control, perforated leather upholstery, 12-way active multicontour power-adjustable seats, heated seats, memory settings, a power-operated wind blocker panel, an auto-dimming rearview mirror and cruise control. Technology features include Bluetooth phone and audio connectivity, Mercedes' COMAND electronics interface and mbrace telematics systems, a navigation system and an 11-speaker Harman Kardon surround-sound audio system with a CD player, satellite radio, HD radio and USB/iPod interface.

The most notable option on the SL400 is a Premium package that bundles a rearview camera, an automatic parallel parking system, ventilated seats with massage, the AirScarf neck-area heating system, keyless entry and ignition and a power trunk closer. The SL550 includes all of the above, and adds a more powerful V8 engine and front and rear parking sensors.

Both the SL400 and SL550 are also available with a Sport Wheel option package that includes 19-inch alloy wheels, larger front brakes with painted calipers and drilled rear brake discs, plus a sport steering wheel accented with perforated leather trim and silver shift paddles.

The high-performance SL AMG features an even more powerful V8 engine, a limited-slip rear differential, 19-inch alloy wheels, Active Body Control suspension with more aggressive tuning, upgraded brakes and a higher top-speed limiter. The cabin gets illuminated door sills, upgraded leather upholstery and an AMG Performance Media system that can display G-forces and other related information.

A Driver Assistance option package that includes adaptive cruise control, a blind-spot warning system and active lane-keeping assist is available on the SL400, SL550 and SL AMG.

The top-of-the-line SL 65 AMG gets a V12 engine, 19-inch front and 20-inch rear wheels, the contents of the Driver Assistance option package, a panoramic roof with a Magic Sky feature that darkens the tint at the touch of a button, soft-closing doors, a night-vision infrared camera system, a split-view front entertainment system and a premium 12-speaker Bang & Olufsen audio system. Both the AMG models can also be optioned with an exterior Carbon Fiber Trim package that includes a carbon-fiber front airdam, mirror covers and rear spoiler. The AMG High-Contrast Styling package includes distinctive 19-inch front and 20-inch rear alloy wheels, a gloss black hardtop and rear spoiler, black chrome exhaust tips, a performance steering wheel and unique interior trim. Carbon-ceramic high-performance brakes are also available.

Stand-alone options include 19-inch alloy wheels, upgraded designo leather upholstery and interior trim, plus many of the features found on the two AMG models.

The new 2015 Mercedes-Benz SL400 is propelled by a turbocharged 3.0-liter V6 that produces 329 horsepower and 354 pound-feet of torque. The SL550 gets a turbocharged 4.7-liter V8 engine that puts out 429 hp and 516 lb-ft of torque. Both engines come mated to a seven-speed automatic transmission and rear-wheel drive.

Naturally, EPA estimated fuel-economy varies by engine. A standard automatic engine stop-start system helps the SL400 earn a respectable EPA estimated fuel-economy rating of 23 mpg combined (20 city/27 highway), while Mercedes-Benz claims acceleration to 60 mph should take about 5.1 seconds.

The SL550's numbers are a still decent 20 mpg combined (18/25), and in Edmunds testing, the SL550 accelerated from zero to 60 mph in just 4.4 seconds.

Powering the SL AMG is a turbocharged 5.5-liter V8 that pumps out 577 hp and 664 lb-ft of torque. The transmission is a specialized seven-speed automatic with quicker shifts than the standard version. The EPA rates the SL at 19 mpg combined, while Mercedes conservatively projects a 4.1-second sprint to 60 mph.

Finally, the SL 65 AMG comes fitted with a turbocharged 6.0-liter V12 that's rated at an impressive 621 hp and 738 lb-ft of torque, mated to the same specialized seven-speed automatic transmission. In Edmunds testing, the SL 65 AMG sprinted to 60 mph in just 3.9 seconds. EPA fuel economy ratings drop to 17 mpg combined.

Standard safety features on the 2015 Mercedes-Benz SL-Class include antilock brakes with automatic brake drying, stability and traction control, head- and thorax-protecting side airbags and knee airbags. Also standard are roll bars that automatically deploy, a PreSafe system that can tighten the seatbelts, adjust the seats and roll up the windows if a collision or rollover is deemed imminent, and Attention Assist, a feature that monitors a number of variables and will sound a warning if it detects signs that the driver may be becoming drowsy.

A rearview camera (optional on the SL400) and mbrace2 safety telematics are also standard, the latter of which includes automatic collision notification, an SOS button, stolen vehicle location, alarm notification and remote door lock/unlock.

The main safety option on SL models is the Driver Assistance package (standard on the SL 65 AMG) that includes adaptive cruise control with pre-collision braking, plus active lane-keeping assist and active blind-spot assist, both of which can automatically intervene if sensors detect a potentially dangerous situation.

In Edmunds brake testing, the SL550 came to a stop from 60 mph in 114 feet, which is a bit long for such an expensive performance car with summer tires. The SL 65 was better, with a stopping distance of 108 feet.

While the long list of techno-gadgetry and top-quality materials go a long way to bolstering the Mercedes SL-Class' "yes, you can have it all" image, driving this luxury roadster seals the deal.

While we have yet to drive the new SL400 model, we can say its SL550 sibling is among the most accomplished sports cars on the road, with an abundance of acceleration, powerful brakes and exemplary handling capabilities, especially when fitted with the available Active Body Control suspension option that all but eliminates body roll. Perhaps more remarkable is the fact that in normal everyday motoring, the SL's smooth ride and sophisticated transmission give it an air of relaxed refinement that is decidedly uncommon in cars with this much performance potential, even the mightiest SL 65 AMG which earned an Edmunds "A" rating.

Those seeking to make a substantial impression on passers-by will likely find themselves lusting for one of the two AMG models, by virtue of their sexier stance and more muscular engines. With these, however, it's mostly style points or bragging rights, as the SL550 offers all the power and handling anyone could realistically ever take advantage of in a street car.

Of course, the big problem with having everything (or nearly everything) is where to put it. In this regard, the 2015 Mercedes SL-Class is a model of efficient use of space.

For example, Mercedes designers and engineers have managed to pack the passenger cabin with an enormous amount of technology without making the cockpit look overly cluttered. Accessing most of these features is done via the COMAND system's console-mounted knob, which calls up menus on the 7-inch center display. Worthy of special mention are unique features like the optional SplitView central display that allows the driver and passenger to see their own unique content like the nav system's map and a DVD movie simultaneously.

In more practical terms, head- and legroom are abundant, and the 12-way power-adjustable seats offer a particularly large amount of fore-and-aft travel which, combined with the power tilt-and-telescoping steering wheel, makes it easy for a wide range of individuals to find an ideal driving position. The sun-reflective perforated leather upholstery offers heating, ventilation and a massage function that makes the SL an excellent road-trip machine. Add the power mesh wind blocker that rises from behind the seats and the AirScarf neck-level heating system and it becomes possible to enjoy open-air motoring in conditions where owners of lesser convertibles feel compelled to put the top up.

When it comes to loading up for a trip to the golf course or a romantic weekend getaway, the trunk offers 10.2 cubic feet of storage with the roof up and 7.2 cubic feet with it folded down (there's also a significant amount of storage behind the seats). Accessing the trunk is made easier by a hands-free power opener that can be activated by waving a foot under the rear bumper.