2015 Mercedes-Benz SL63 AMG

The Mercedes-Benz SL63 AMG is a hardtop convertible that seeks to strike an ideal balance between prodigious performance and coddling luxury. The SL63 AMG slots between the standard SL550 and the V12-powered SL65 AMG in Mercedes' SL-Class lineup.

Recent Changes
For the latest model year, the SL63's twin-turbocharged 5.5-liter V8 engine has been upgraded to churn out 577 horsepower and 644 lb-ft. of torque, upgrades of 47 ponies and 54 lb-ft. of twist over the outgoing model.

Overview
SL is short for sport leitch, or "sport lightweight" in English, and Mercedes engineers went to great lengths to remove precious pounds from the SL in order to help it live up to its name. Underneath the sheetmetal is a low-weight aluminum bodyshell not unlike the one used in the SLS AMG supercar. High-strength steel is incorporated at key points to enhance rigidity, and carbon fiber used on the trunk lid's inner frame also helps trim weight. As a result, the SL tips the scale at a hair over 4,000 pounds.

To stand apart from the less powerful SL550, the SL63 AMG gains its own unique body kit and AMG-specific LED running lamps. Special V8 Biturbo badging hints at what provides motivation. At the rear, a small spoiler lip improves aerodynamics and stability, while a sport exhaust system exits through a unique air diffuser.

Life Aboard
Inside, the SL63 features a sporty, driver-focused cockpit with two bucket seats and a sporty three-spoke multi-function steering wheel. The instrument cluster is made up of four analog gauges and a configurable thin-film transistor screen that provides vital information about the car and its surroundings.

The SL comes standard with a high-resolution color touch screen that runs Mercedes' COMAND infotainment system. COMAND groups the SL's navigation, entertainment and connectivity functions into a single unit that can also be controlled using a controller knob on the center console, voice commands and buttons on the steering wheel.

The SL63 also comes with mbrace, a system which includes a host of cloud-based goodies including a concierge service, location-based traffic and weather updates, stolen vehicle location assistance, automatic collision notification and more. Available apps add internet browsing, Google local search with street view, Yelp reviews, Facebook access and news reports. Owners can even use an mbrance smartphone app to remotely lock, unlock or locate their SL63.

Under the Hood
The SL63 was designed as more of a high-performance grand-tourer than an all-out sports car. It is powered by a hand-built twin-turbocharged 5.5-liter V8 engine that pumps out 577 horsepower at 5,500 rpms and 664 lb-ft. of torque at 2,000 rpms. Power is sent to the rear wheels via a seven-speed automatic transmission that can be controlled by shift paddles mounted behind the steering wheel.

The SL63 AMG reaches 60 mph from a stop in 4.1 seconds. An AMG-modified active sports suspension and upgraded brakes on all four corners ensure improved handling over the standard SL roadster.

Fuel economy checks in at 16 in the city and 25 on the highway thanks in part to a standard start/stop system.

Standard and Optional Features
The SL63 AMG comes standard with a universal garage door opener, an auto-dimming rear-view mirror, heated power-adjustable door mirrors, HID headlights, rain-sensing wipers, leather upholstery on the seats and on the steering wheel, power-adjustable front seats that are both heated and cooled, dual-zone automatic A/C, navigation and 19-inch alloy wheels.

Highlights from the long list of options include additional alloy wheel designs and paint colors, a carbon fiber exterior package, red brake calipers, an AMG performance steering wheel, an upgraded sound system, soft-close doors and carbon ceramic brakes.

Occupant Safety
In addition to traction and stability control systems, the SL63 AMG boasts six supplemental restraints including two-stage front airbags, dual knee airbags and dual side airbags. Roll over hoops mounted behind the seats provide an extra measure of protection.

Also standard is an Attention Assist system that can alert the driver to the first signs of drowsiness, a factor that causes more than 100,000 accidents a year in the U.S.A. A steering sensor is coupled to smart software that uses 70 parameters to establish a unique driver profile during the first 20 minutes of driving. Between 50 and 112 mph, the system identifies the erratic steering corrections drivers make as they begin to get drowsy and triggers an audible warning and a "Time for a Rest?" message with a coffee cup icon in the instrument cluster.

The optional Driver Assistance package bundles electronic driving aids like a radar-based adaptive cruise control, Blind Spot Assist, Pre-Safe brake and active lane keeping assist.

Key Competitors
Those in the market for a powerful roadster that's also a comfortable highway cruiser should also consider alternatives to the SL63 AMG like the Jaguar XKR Convertible, the Maserati GranTurismo Convertible Sport and the Porsche 911 Carrera S Cabriolet.