Mercedes-Benz is giving its flagship roadster a power boost for the 2015 model year. The SL63 AMG's twin-turbocharged 5.5-liter V-8 gets a hefty 48-horsepower increase, bringing total output to 585 horsepower--matching that of the upcoming 2015 Mercedes-Benz S63 AMG coupe, and making both cars the most powerful vehicles yet to carry this particular engine.
http://www.motorauthority.com/news/1091369_more-power-for-mercedes-benz-sl63-amg
http://www.motorauthority.com/news/1091369_more-power-for-mercedes-benz-sl63-amg