New 2018 MercedesBenz SL Convertible New 2018
MercedesBenz SL Convertible

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KBB Editor's Overview

By Editorial Staff

The 2018 Mercedes-Benz SL is the flagship roadster from the German luxury brand. With roots dating back six decades, the SL boasts high-end class, gracious performance and a distinguished history. Today’s SL, though, is thoroughly modern. It features robust technology and amenities, with the ability to automatically keep you in lanes while massaging your back. This 2-seat convertible stands out against potential competitors such as the Porsche 911 and Jaguar F-Type not just for its more substantial size and comfier driving manners, but in that it’s essentially two cars in one. Thanks to a retractable hardtop, the SL transforms from coupe to convertible in seconds. At nearly $90,000 for a base V6 model, the SL also guarantees envy and exclusivity.


You'll Like This Car If...

If power and prestige are as important to you as comfort and luxurious accouterments, they all converge in the 2018 Mercedes SL. Equally beneficial is a retracting hardtop roof that morphs the SL from secure coupe to wind-in-your-hair convertible. Even higher-power Mercedes-AMG models are available (and reviewed separately).

You May Not Like This Car If...

If a price that begins near -- and can easily exceed -- six figures doesn’t already deter you from the Mercedes-Benz SL, you may reconsider if you crave a purer sports car rather than a grand tourer. If that’s the case, the Porsche 911 and Jaguar F-Type offer more edge.

What's New for 2018

There are only minor updates for the 2018 Mercedes-Benz SL. Among them are a standard rearview camera for SL450 models and an AMG sport steering wheel in leather/Dinamica that’s standard across the model line.

Driving It

Driving Impressions

Despite having two seats and a long hood that packs a turbocharged V6 or V8, the Mercedes-Benz SL isn’t a sports car per se. Yes, it can rip from 0 to 60 mph in the 4-second range, but razor-sharp handling isn’t its calling card, nor has it ever been. This is a grand touring machine with grace, presence and power. This flagship Mercedes convertible is as much about luxury and comfort as it is performance. It won’t out-handle a Porsche on a mountain road, but for weekend trips and -- let’s be honest -- even everyday driving, you’ll likely appreciate its sense of ease far more. The SL’s optional Active Body Control virtually eliminates body roll, while driving aids like adaptive cruise control with steering pilot take some of the stress out of commuting. The standard 9-speed automatic transmission is among the more refined of its type that we’ve tested. The standard 4-mode Dynamic Select system makes a notable difference in the behavior and feel of the transmission, steering and throttle, especially when switching from Comfort to Sport+.

Favorite Features

Upgraded in power just last year, the V6-powered 2018 SL450 closes the gap between it and the V8-powered SL550. Moreover, it’s $24,000 less than a base 550. Among SL models, it’s a Mercedes-Benz bargain.

This feature, a $2,500 option, remains one of the coolest tricks we’ve seen on a car. At the touch of a button, Magic Sky Control instantaneously alters the transparency of the SL’s glass roof panel, changing from light to dark to let in or keep out sunlight depending on your preference.

Vehicle Details


The SL roadster has yet to receive the lavish, flush-mounted switchgear and massive display screens of its siblings like the S-Class Cabriolet, but it’s luxurious nonetheless. Sixteen-way power-operated seats with sun-reflecting leather upholstery are supportive and functional. Even those over 6-feet tall can be comfortable, a rarity in roadsters. Cabin storage is at a premium, but there’s plenty in the trunk -- a usable 13.5 cubic feet that can accommodate two golf bags (you are driving this to the country club, right?). Back inside, we recommend treating yourself to the Airscarf system that blows warm air on your neck. It gives further reason to drop the top on a chilly evening.


The 2018 Mercedes-Benz SL is among the rare convertibles that look equally good with the top up or down. That’s because its retractable top is made of metal instead of fabric. In the up position, the SL looks like a traditional coupe. Lowered, it’s a sun-seeking status statement. Even with the top up, there’s a sense of airiness thanks to a standard glass panorama roof. Up front, the Mercedes SL honors its forebears with a long, sleek hood and a taut tail. An update for 2017 freshened the front-end styling, keeping the latest SL looking sharp and elegant.

Notable Standard Equipment

As expected of a luxury convertible costing nearly $90,000, even a base Mercedes-Benz SL450 comes highly equipped. Notable standard features include leather upholstery, heated and 16-way power seats, dual-zone climate control, power trunk, universal garage remote, and 19-inch wheels. The Mercedes SL’s COMAND infotainment system bundles a central high-res display with navigation, Apple CarPlay and Android Auto smartphone connectivity, and a 600-watt harman/kardon audio system with 6-disc CD player, dual USB inputs and Bluetooth streaming. Standard safety systems include eight airbags, rollbars that instantly deploy in a rollover, a system that monitors for driver drowsiness, and another system that can automatically stop the car if a frontal collision appears imminent. In addition to a V8 engine, SL550 models have massaging front seats that are also ventilated, the Airscarf neck-heating system, hands-free power trunk, and power-operated soft-close doors.

Notable Optional Equipment

As is the norm for a European luxury car, there are numerous ways to enhance the 2018 Mercedes SL-Class. Standout stand-alone options include the Magic Sky Control (see Favorite Features), a wood and leather steering wheel, and a wonderful Bang & Olufsen audio system. An in-car Wi-Fi system is also available. Packages include driver-assistance features like blind-spot monitoring, adaptive cruise control, and active lane-keeping assist. Optional on the SL450 (and standard on the SL550) is the Premium Package with massaging and ventilated seats, hands-free trunk, Airscarf, and a parking-assist system that can parallel park the car.

Under the Hood

The Mercedes SL450 uses a 3.0-liter twin-turbo V6 that makes 362 horsepower and enables 0-60-mph runs of 4.9 seconds. That’s quicker than most drivers will ever need, but for those craving a traditional V8, the SL550 houses a 4.7-liter twin-turbo V8 good for 449 horsepower and a 0-60-mph run of 4.3 seconds. Even faster are the Mercedes-AMG variants, the top of which has a 6.0-liter twin-turbo V12. Those variants are reviewed separately. The SL450 and SL550 use a 9-speed automatic transmission, and keep tradition with standard rear-wheel drive. To save fuel, a start/stop system shuts off the engine at idle, such as at stoplights. If you find the restarts annoying, the system can be deactivated with the press of a button.

3.0-liter twin-turbocharged V6 (SL450)
362 horsepower @ 5,500-6,000 rpm
369 lb-ft of torque @ 1,800-4,500 rpm
EPA city/highway fuel economy: 20/28 mpg

4.7-liter twin-turbocharged V8 (SL550)
449 horsepower @ 5,250-5,500 rpm
516 lb-ft of torque @ 1,800-3,500 rpm
EPA city/highway fuel economy: 17/25 mpg


Pricing Notes

The 2018 Mercedes-Benz SL-Class has a Manufacturer’s Suggested Retail Price (MSRP) starting at $89,195. That’s hardly cheap, but quite a bit less than a V8-powered Mercedes SL550, which begins at $113,295. Of course, add some options and these prices can easily rise by thousands. There are few direct rivals to the SL, but for comparison a Porsche 911 Carrera Cabriolet, which features a fabric top vs. the Mercedes’ hardtop, starts over $104,000. On the higher end of the scale, a Maserati GranTurismo convertible starts over $150,000, while a Bentley Continental begins over $220,000. On the lower end are the Jaguar F-Type and the SL’s own smaller brother, the Mercedes-Benz SLK, also a hardtop convertible. Before indulging in your luxury convertible, check the Fair Purchase Price to see what others in your area are paying. The Mercedes SL’s resale value isn’t particularly good, and at these prices its depreciation is sizable after just a few years.

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