The venerable Mercedes-Benz SL-Class two-seat roadster receives a number of updates for 2011, including a reshaped exterior with a larger air dam up front, aerodynamic side grilles, dual trapezoidal exhaust tips, and new exterior mirrors inspired by the SL's racing heritage. However, the SL retains some of its most iconic features, including its classic single-bar grille and a power-retractable aluminum hardtop, which opens and closes in 16 seconds, transforming the SL from a coupe to a roadster. As the roof retracts, the rear window pivots 180 degrees, so it occupies minimal space in the trunk, ensuring room for luggage and other cargo. In addition, the SL's pop-up roll bar, which Mercedes developed and debuted on the roadster, deploys in just 0.3 seconds to help protect passengers in the event of a rollover. Mercedes offers the SL-Class in SL550, SL63 AMG, and SL65 AMG trims for 2011, each powered by a different engine. The lineup starts off with a 5.5-liter, 382-hp V8, which powers the SL550. Tuned to emit a mellow rumble, the V8 generates 391 lb-ft and drives the SL from 0-60 in 5.3 seconds. It links to a seven-speed automatic transmission with Touch Shift, which enables drivers to manually shift gears using steering-wheel-mounted paddle shifters. The EPA estimates fuel economy numbers for the V8 at 13/21 mpg. Stepping up a notch, the SL63 AMG sports a hand-crafted 6.3-liter, naturally aspirated V8 engine, which puts out 518 hp and 465 lb-ft of torque. The technically advanced engine was the first powerplant developed from the ground up by AMG, Mercedes' in-house sport tuner, and shares no parts with any other Mercedes-Benz engine. It mates to a new AMG Speedshift MCT seven-speed transmission, which provides both automatic and manual shifting, as well as four driving modes (Comfort, Sport, Sport Plus, and Manual) and a race start function. The powerplant manages fuel economy numbers of 12/19 mpg. At the top of the line, the SL65 AMG comes equipped with a 6.0-liter, twin-turbocharged V12, which blasts out 604 hp and a mind-boggling 738 lb-ft of torque. The big V12 mates to an AMG Speedshift five-speed automatic, and propels the SL65 from 0-60 mph in 4.2 seconds. Fuel economy numbers check in at 11/18 mpg. Inside, the SL-Class displays a cabin worthy of one of the world's elite roadsters. A sweeping console, trimmed in hand-polished Burl Walnut, divides the 12-way power-adjustable heated front seats, which are covered with hand-crafted leather. A leather-wrapped multifunction steering wheel, aluminum door-sill trim, dual-zone climate control, Bluetooth, and electronic climate control all come standard. To keep passengers entertained, Mercedes includes a 10-speaker, 510-watt Harman Kardon audio system with Sirius satellite radio, HD radio, a 6-DVD/CD player, and a 4GB music storage system. In addition, a hard-drive-based navigation system with Zagat ratings comes as standard equipment. The SL63 and SL65 add such standard features as AMG heated/ventilated sports seats with Nappa leather, carbon fiber interior trim, an AMG instrument cluster, and AMG sill panels. In addition, the AMG trims ride on an AMG sports-tuned suspension and feature an AMG high-performance braking system. Mercedes offers a wide range of options for the SL-Class, including multicontour seats (on the SL550), an Airscarf neck-level heating and ventilation system, and the SL's new Direct Steer system, which provides precise and responsive handling, especially in tight turns. Safety features for the SL include electronic stability control and antilock brakes with brake control. The rear-wheel-drive SL550 rides on 18-inch staggered-width alloy wheels, while owners can add optional AMG wheels with perforated rear brakes.