A new generation of the Mercedes-Benz SL-Class comes around about once a decade. When it does, it's an occasion. Just about everything has been redesigned or changed for this sixth-generation 2013 Mercedes-Benz SL-Class, yet it pleasingly maintains its rightful place as a long-standing icon.

For 60 years, SL has stood for Sporty Lightweight. But SLs haven't qualified as light since the early 1970s, and the most recent SL was a porker. Weight-saving has been a priority this time around. The body is now 90 percent aluminum, and the SL's curb weight is down to around 4,000 pounds, or about 400 pounds less than the previous-generation model.

This weight loss is noticeable from the driver seat. The new SL-Class just feels lighter and less bulky on its feet. It also helps that there's even more power under the hood. The naturally aspirated 5.5-liter V8 that made 382 horsepower is history, replaced by a 429-hp 4.7-liter V8 with twin turbos, direct fuel injection and auto start/stop technology. Along with a new seven-speed automatic transmission, it also delivers up to 30 percent better fuel economy. The SL63 AMG gets a new engine as well, a 5.5-liter twin-turbo V8 good for 530 hp.

Besides performance, the SL easily exceeds its other expected qualities. There's the supremely smooth ride, an uncommonly elegant and quiet cabin and seats that pamper for hours -- or until the fuel tank runs dry. The SL also provides new safety equipment, useful connectivity and entertainment options and one of the industry's first glass roof panels that changes from nearly clear to smoky dark with the push of a button. This combination of technology and craftsmanship is part of the reason the SL remains so relevant and trend-setting.

Natural competitors include the Audi R8 Spyder, BMW 6 Series Convertible and the equally iconic and recently redesigned Porsche 911 Cabriolet. All offer high-performance versions. One could also consider the Aston Martin V8 Vantage, Ferrari California, Jaguar XK and Maserati GranTurismo convertibles. Yet the 2013 Mercedes-Benz SL is still such a compelling automobile because it seems to blend sports car, luxury car and grand touring car better than some manage to be any one of those things alone. And that's what makes an icon an icon.

The 2013 Mercedes-Benz SL-Class is a two-seat convertible with a retractable hardtop that is available in SL550, SL63 AMG and SL65 AMG trims.

The SL550 comes standard with a twin-turbo 4.6-liter V8, 18-inch wheels, a driver-selectable adaptive suspension, LED running lights, active bi-xenon headlamps, automatic high-beams, dual-zone automatic climate control, 12-way power seats (with heating, four-way lumbar adjustment and memory functions), sun-reflective leather upholstery, walnut- or ash-burl wood trim, a multifunction power tilt-and-telescoping steering wheel with shift paddles, auto-dimming rearview and driver-side mirrors, a power wind deflector and a power trunk lid.

Telematics and entertainment are covered by a hands-free Bluetooth-enabled telephone system, a navigation system, real-time traffic, voice controls and a 10-speaker Harman Kardon surround-sound audio system with a six-CD/DVD changer, satellite radio, HD radio, digital music storage and an iPod/USB media interface.

For added performance, the SL550's options include 19-inch wheels with high-performance tires, upgraded brakes, a sport steering wheel and an even more advanced, active suspension system. For added comfort and convenience, Mercedes also offers keyless ignition/entry, soft-close doors, a glass roof panel with adjustable transparency, a premium leather seating package, ventilated seats, dynamic and massaging seats, plus the AirScarf system that gently blows warm air on your neck. Also available are a wood steering wheel and power trunk that opens via a swipe of your foot beneath the rear bumper, and a Bang & Olufsen 12-speaker sound system.

The SL63 AMG is a high-performance variant that features a more powerful 5.5-liter twin-turbo V8, different 19-inch wheels and various AMG-tuned components (suspension, brakes, exhaust) and AMG-specific styling flourishes. The AMG Performance package adds greater engine output, a limited-slip differential, a more aggressively tuned suspension, forged alloy wheels, a beefier steering wheel and a higher top speed. Carbon-composite brakes and two more wheel choices plus a carbon-fiber kit are also available.

The SL65 AMG is outfitted much like the SL63 with one very large exception: a 6.0-liter twin-turbo V12. It also lists as standard equipment nearly all of the SL550's optional equipment, such as keyless ignition/entry, soft-close doors, a glass roof panel with adjustable transparency, a premium leather seating package that includes heating and massaging 12-way power seats, plus the AirScarf system. Also, the navigation system, Bang & Olufsen audio and adaptive cruise control are standard. Optional equipment is limited to carbon-composite brakes and trim and styling options in carbon fiber.

To coincide with the launch of the 2013 SL-Class, there will be a very special "Edition 1" model for a very limited period. It will include AMG 19-inch alloy wheels, exclusive red/black leather with contrasting top stitching, AirScarf, the Harman Kardon audio system and special paintwork.

The rear-wheel-drive 2013 SL550 is powered by a new 4.6-liter twin-turbo V8 that produces 429 hp and 516 pound-feet of torque. Combined with automatic start/stop technology and a more fuel-efficient seven-speed automatic transmission, it earns an EPA-estimated 17 mpg city/25 mpg highway and 20 mpg combined. In Edmunds testing, we recorded an impressively quick 4.4-second 0-60-mph time.

Opting for the SL63 AMG upgrades to a new 5.5-liter twin-turbo V8 that produces 530 hp and 590 lb-ft of torque. It's also paired to a seven-speed automated manual transmission. An optional performance package ups the engine's output to 557 hp and 664 lb-ft of torque. This SL63 will accelerate to 60 mph in less than 4 seconds by Mercedes' estimation. The EPA gives it a 16 mpg city/25 mpg highway and 19 mpg combined rating.

The SL65 AMG comes with a 6.0-liter twin-turbo V12 that churns out 621 hp and 738 lb-ft of torque. For 2013, the venerable V12 is also hooked up to a seven-speed automatic. In a recent Edmunds test, the SL65 AMG ran from zero to 60 mph in just 3.9 seconds. The EPA estimates fuel economy at 14/21/17 mpg.

Standard safety features on the 2013 Mercedes-Benz SL-Class include side airbags, new head airbags, knee bags for both driver and passenger, stability and traction control and antilock brakes with automatic brake drying. Also standard are automatically deploying roll hoops, an automated pre-collision system (it tightens belts, adjusts the seats and even rolls up the windows if it senses an imminent roll-over) and a sophisticated drowsy driver alert system.

The usual suite of safety options now includes front and rear parking sensors that scan available spaces and enable automated parking. A rearview camera and adaptive cruise control with pre-collision braking are familiar options, but active lane-keeping assist and active blind-spot assist both will apply a single brake to help guide the car back into its lane.

A new suite of connectivity is standard on the SL. Mercedes calls it mbrace2 and it combines advanced cloud-based and GPS technology and Web applications with 24-hour support from helpful experts. The mbrace hardware is standard, and a trial period for each of the three mbrace packages is included.

Mercedes-Benz is proud of its repeat buyers, and perhaps even more proud of its repeat SL buyers, of which we're told 40 percent opt for an AMG version. After one drive in a 2013 SL550, we know why. It simply did everything we asked of it -- both at the track and on the road.

The new turbocharged V8 offers effortless, seemingly endless power. The transmission is perhaps one of the most intelligent and responsive we've ever sampled, while the adaptive suspension should be an industry standard when it comes to composure and compliance. The inherent grip and agility will exceed most enthusiasts' expectations with ease -- and that was before we even drove the SL63 AMG.

The 2013 Mercedes-Benz SL-Class has an ability to mask its impressive feats of performance with a silky-smooth presentation. It has a wide range of talents that makes it exceptional to drive anywhere. Few cars offer this much fun in as many environments. Accelerating to enter a freeway, cruising along the coast with the top down or racing up a mountain road, the SL always manages to put a smile on our face and every drive has a sense of occasion and is cause for celebration.

In terms of overall interior design, the SL is one of very few automobiles that masterfully blends rich, genuine materials, honest and obvious craftsmanship, and truly industry-leading technology. All too often we witness carmakers showcasing their advanced technology while sacrificing aesthetics and ergonomics, but not Mercedes-Benz. The SL's interior is both inviting and elegantly simple in its function. The presentation, execution and function are all top-notch.

If that won't impress your friends, the Magic Sky Control push-button tinted glass roof will. Mercedes says at its darkest setting, the thermal energy entering the cabin is less than a household light bulb. And even in its fully transparent mode, both UV and infrared rays are effectively blocked, helping keep the cabin cooler. Lowering the top is equally impressive. At less than 20 seconds in either direction, the geometric ballet never gets old.

For a roadster, the SL offers good cargo capacity and storage. With the top up, it holds 10.2 cubic feet of luggage and 7.2 cubic feet when the top is stowed. Mercedes' "Easy Pack" feature allows access to luggage even with the top stowed in the trunk. The cabin has good small storage and there's a surprising amount of room (and a generous bin) behind the seats.