Introduction

The richly luxurious Mercedes-Benz SL-Class is a two-seat grand touring sports car. The Mercedes-Benz SL400 and SL550 put the emphasis on grand touring, blending nimble road behavior with nearly effortless power. Its crisp body lines look forceful at the front end, and particularly charming with the convertible top down. 

The SL-Class was most recently redesigned for 2012, but the nameplate has roots going six decades back. Four SL-Class versions are available, identified by engine. 

The SL400 uses newly developed V6, a 3.0-liter twin-turbocharged engine that develops 329 horsepower and 354 pound-feet of torque, mated to a 7-speed automatic transmission. 

The SL550 comes with a twin-turbo 4.7-liter V8 produces 449 horsepower capable of accelerating to 60 mph in 4.5 seconds. 

Two AMG editions round out the lineup, delivering the kind of acceleration suggested by the racy body. The SL63 AMG offers a balanced blend of power and handling prowess. Its brawny twin-turbocharged, AMG-built V8, generating 530 horsepower, works with a wet-clutch 7-speed AMG automatic transmission. Acceleration to 60 mph takes just 4.1 seconds. A Performance Package boosts output to 557 horsepower and 664 pound-feet of torque. Up top is the SL65 AMG, packing a twin-turbo V12 good for 621 horsepower and 738 pound-feet and a 7-speed automatic. 

Each model stands ready to deliver relaxed luxury along with willing power, as well as nimble maneuvers when needed. Twin-turbo V8s, in particular, can provide an exceptional surge of energy. Driving one of these can become intense, but only if that's your preference. If not, you can expect relaxed cruising, surrounded by luxury. 

All SL-Class models have Mercedes-Benz's COMAND infotainment system, including a 7-inch display screen, DVD changer, and Web browsing. Optional comfort features include Airscarf, which sends warm air to the driver's neck. The folding hardtop can have Magic Sky Control, which turns the roof's glass panel dark. A premium Bang & Olufsen sound system can replace the standard Harman/Kardon setup. 

Changes are few for 2016, as a redesigned SL-Class is scheduled for the 2017 model year. 

Lineup

Four levels of power are available in the SL-Class:

SL400 ($85,050) contains the 3.0-liter V6 and comes with leather upholstery, wood trim, 12-way power seats, dual-zone automatic climate control, Bluetooth, navigation, ambient lighting, a heated windshield, and 18-inch run-flat tires. Harman/Kardon surround sound has 10 speakers. 

SL550 ($108,050) moves up to the 449-horsepower, 4.7-liter V8. 

SL63 AMG ($149,700) gets the 530-horsepower, 5.5-liter V8. 

SL65 AMG ($217,550) is powered by a 6.0-liter V12 engine. 

Standard safety features include active headlights and LED daytime running lights. Attention Assist is standard, but a rearview camera is part of an option package. The Driver Assistance Package bundles Pre-Safe braking, adaptive radar cruise control, blind-spot assist, and lane-keeping assist. Pop-up rollbars are designed to activate in a rollover. 

Walkaround

Over its long history, the SL-Class has gone through a succession of design generations, but a distinctive appearance tends to bind them together. Sporty and bold, the 2016 SL-Class is long and wide. From the rear, it appears related to the smaller SLK. 

The overall look is uneven, as if the rear end belongs on a different vehicle. With the top raised, the roofline's slope and the teardrop-shaped taillamps seem out of sync with the imposing front end. With the top down, the difference is less noticeable. 

Overall, the SL-Class has a formal profile with a large nose, somewhat like its Sixties ancestors. A big grille and air dams prevent the car from looking overly large or heavy. 

Interior

Space is abundant and fittings excellent in the inviting two-seat cockpit, which has a technical feel. Aviation-type vents are complemented by a large LCD screen and a bounty of metallic trim. The steering wheel's bottom is slightly flat, and the driver grasps a short shift lever on the console. 

Wide, supportive seats can accommodate a broad range of body types, keeping each one snug, with plenty of shoulder and elbow room, as well as a cushion extender. Space behind the seats, in contrast, is minimal: just enough to hold a briefcase. A pair of roller suitcases might fit in the trunk if the top is raised, but not when it's down. With the roof up, getting in demands some bending. 

Controls are logically grouped, but not necessarily marked well. The navigation system is integrated with infotainment features, using the COMAND controller. 

Driving Impression

The SL-Class is a luxurious and sport touring roadster, with overtones of the original Ford Thunderbird. In addition to abundant power in a choice of levels, Direct Steer electric power steering helps provide a nimble, engaging road experience. Steering might lacks some feedback, but proper weight balance helps give the SL-Class in a neutral attitude in tight curves. 

Active Body Control is available. Although it limits body roll, the active suspension fails to add much to the driving experience. The conventional suspension in the SL400 feels more natural and predictable. 

As expected, the V6-powered SL400 is likely to travel at a more leisurely pace than its more potent siblings, though Mercedes-Benz claims a 5.1-second 0-60 mph time, which is very quick. The 7-speed automatic has paddle shifters, and the SL400 is a consistent performer. Because power develops at low engine speed, the V8-powered SL550 yields impressively potent acceleration. 

The SL63 AMG amounts to a serious step upward in performance, and has a more exotic character, as well as a lusty engine note. With its V12 engine making 621 horsepower, the SL65 AMG could be considered overkill. Greater weight limits its agility, and it's only slightly swifter than the SL63. 

As for economy, the SL400 is the thrift leader, EPA-rated at 20/27 mpg City/Highway. The SL550 is EPA-rated at 16/24 mpg, while the SL63 AMG manages 16/25 mpg and the SL65 shrinks to 14/21 mpg. 

Summary

The SL-Class is a luxurious tourer. Look for deals on the 2016 models in preparation for the next-generation. Few sport/touring car fans are likely to be disappointed with an SL400 or SL550. 

Driving impressions by Kirk Bell, The Car Connection. James M. Flammang contributed to this report.