First Drive: 2012 Mercedes-Benz CLS63 AMG

Though acceleration is appropriately willing under light throttle, a stab of the gas punches this 4114-lb car through space with tenacity, good for 0-to-60-mph jaunts in a claimed 4.4 seconds, or 4.3 ticks with the performance package. In contrast to the standard issue CLS, the CLS63's seven-speed transmission ditches a torque converter for a wet startup clutch, and shifts occur smoothly and swiftly, with extra alacrity and added steering stiffness when you click from "C" (comfort) to "S" (sport), S+, or M (manual.) Ride quality is firm and sometimes jarring, getting stiffer with more aggressive settings. But high entry speeds are rewarded with surprising feedback from the electromechanical steering, making this sixteen-foot car feel taut and nimble on tight roads. The "AMG" button amps up everything from shift times to suspension damping, offering downshifts that are seemingly prescient and shotgun-quick. Though not quite as aurally expressive as the normally aspirated 6.2-liter engine, the new twin-turbo nonetheless grunts and growls and snorts between shifts. The engine's stop/start feature only activates in "C" mode, and sudden throttle can produce abrupt lurches from a standstill; it's best to ditch Eco mode if you prefer quick, smooth getaways. While our performance package-equipped tester may have felt incrementally quicker (or was our interior dynamometer simply drunk on horsepower?), its massive carbon ceramic brakes definitely added a more dramatic bite to deceleration, as though all four tires were digging in like cleats on Astroturf. Bulked up but not brawned out, the 2012 CLS63 offers an appreciable improvement in speed, fuel economy, and, arguably, styling over its antecedent. The first-generation CLS apparently needed time for consumers to become accustomed to its then-radical shape, as it had its best sales in 2010, its last full year on the market. Based on our drives of both the regular CLS and the new CLS63, both of which hit dealers in June, it seems that Mercedes-Benz has another hit on its hands-long adoption curve, or not. 2012 Mercedes-Benz CLS63 AMG
On sale: June
Price: (estimated) $100,000
Engine: Twin-turbocharged 5.5-liter V-8, 518/550 hp, 516/590 lb-ft
Drive: rear-wheel