Introduced in the mid-1950s, the first Mercedes-Benz SL was the 300SL "Gullwing" coupe, so nicknamed for its doors, which swung upward. The Gullwing was joined a few years later by a convertible version. The model's letters stand for "Sports Leicht" (translated: sports lightweight) and the number(s) refer to the engine size (e.g. 300 means 3.0-liter). The 300SL was the first car to be sold in America with fuel injection and, with proper axle gearing, it could hit nearly 160 mph.

Pretty impressive for any car of that era -- let alone one propelled by a six-cylinder engine! By 1958, a roadster replaced the coupe, adding al fresco enjoyment. As the years passed, the 2006 Mercedes-Benz SL-Class got more luxurious and heavier with each successive redesign. The 1960s brought the 230/250/280 SL roadsters. A V8 replaced the straight six when the car was revamped in 1972 and this version (the car Steve Austin drove in "The Six Million Dollar Man") continued until 1989. After a lengthy run of 18 years, that car was replaced in 1990 by the sleeker but heavier 300/320/500/600 SLs of the 1990s, which once again offered six-cylinder as well as V8 and even V12 power.

By 2002, the last year of that generation, the six-cylinder version was gone. Redesigned again in 2003, the SL500 continues the tradition of an open-air, two-seat grand touring (GT) car with the typical Benz virtues of luxury, safety and capable performance. The newest Mercedes SL, however, offers a more involving driving experience than the previous car. Its rack and pinion steering is more communicative than the old setup, and an active suspension nearly eliminates body roll, providing stunning handling that belies the car's considerable 4,000-pound mass. Another perk of the Mercedes-Benz SL-Class is the retractable hardtop that provides the security and comfort of a coupe when raised and the thrill of open-air motoring when powered down under the rear deck lid.

Still, the 2006 Mercedes-Benz SL-Class is not perfect; operating the audio and navigation systems through the COMAND interface is an exercise in frustration. The 2004 model year saw the return of a V12-powered SL in the form of the SL600, as well as an upgrade to standard SL500 in the form of a new seven-speed automatic transmission. The SL600's mighty V12 boasts nearly 500 horsepower thanks to twin turbochargers, while the extra couple of gears help the SL500 make the most out of its 300-hp V8. Regardless of which model you consider, rest assured that both provide world-class levels of performance, luxury and style that make every drive a memorable one.

The standard Mercedes-Benz SL-Class roadster line consists of the V8-powered SL500 and the V12-powered SL600. Standard equipment on both models includes power-adjustable leather seats, automatic dual-zone climate control, bi-xenon headlights, the remote-access Keyless Go system, a power-retractable hardtop and a high-powered audio system. Options include a sport package for the SL500 that adds 18-inch AMG wheels, high-performance tires and lower body sculpting, Parktronic electronic parking assist and Distronic cruise control, which automatically keeps the Benz a fixed distance from the car ahead of it on the freeway. The SL600 ups the ante with exclusive wheels and interior trim, along with a few additional standard features.

The SL500 sports a 5.0-liter V8 that pumps out 302 horsepower and 339 pound-feet of torque. No manual gearbox is available, but the standard seven-speed automatic allows manual-style gear changes. The SL500 can sprint from zero to 60 mph in around 6 seconds and hit an electronically limited top speed of 155 mph. The 493 horses and 590 lb-ft of torque produced by the SL600's twin-turbocharged 5.5-liter V12 will slingshot that Benz to 60 mph in just 4.5 seconds, though its electronically limited top speed is the same. The SL600 comes with a five-speed automatic.

A slew safety-enhancing technologies are fitted to every Mercedes-Benz SL, including stability control and active body roll control (known as ABC). The SL was the first Benz to get electronic braking, and the system can react much quicker than a conventional hydraulic system and even selectively adjust braking force to each wheel when cornering. Should an accident be unavoidable, there's a multitude of airbags to protect the occupants, including side curtain-style bags that cover the head and torso areas and a knee bag for the driver. The Mercedes SL also has a pop-up roll bar that will deploy if a rollover is imminent.

Apart from the electronically controlled brakes that feel a bit touchy at first, the 2006 Mercedes-Benz SL-Class offers the driver a rewarding experience behind the wheel that rarely grows tiring. Handling is exceptional with almost no body roll and excellent grip. Although the standard SL500 provides brisk acceleration, those looking for the ultimate in top-down performance may want to consider the world-beating acceleration of the SL600's V12 or one of the AMG tuner versions.

A power-operated, retractable hardtop is standard and offers the integrity, insulation and security of a coupe when raised along with the full al fresco experience of a roadster when powered down. The dual-zone climate control is easy to use, but unfortunately the same can't be said for the complex COMAND audio and navigation interface.