The long history of the Mercedes-Benz SL began with a six-cylinder car—the iconic 300SL—but subsequent generations were fitted with ever-larger engines. The U.S.-market lineup currently encompasses the SL550 and SL63 AMG with their twin-turbocharged V-8 engines, as well as the V-12–powered SL65 AMG. These awesome powerplants provide plenty of torque and power, but they somewhat […]