Speaking of stops, the CL63 also incorporates an auto stop-start function-the first appearance of this technology in a non-hybrid Mercedes. Expect this feature to spread in step with the 5.5-liter bi-turbo. It would seem to offer significant city fuel-economy benefits, but we're told its effects don't show up in EPA testing (EPA numbers aren't available at this writing but should be out soon; Mercedes claims the new powertrain overall is 25 percent more efficient than its predecessor).
V-12s still come, to those who wait
Given the enhanced capabilities of the V-8s, the V-12 engines might seem superfluous-and they are, but both V-12 models return nonetheless. The CL600 has the same bi-turbo 5.5-liter twelve as before. It 510 hp is no better than the CL63, and its 612 pound-feet can't equal the performance-enhanced version of the V-8 AMG. The CL65 AMG, meanwhile, retains its 6.0-liter turbo V-12. Now with 621 hp, up from 604 hp, and 738 pound-feet, it remains comfortably atop the pack (and ahead of the new Bentley Continental GT). But-what's this?- it can only tie the 0-60 time, and 186-mph top speed, of the CL63 with the optional performance pack. The CL65 continues to use a five-speed version of the Speedshift automatic, and neither of the V-12s gets the auto stop-start capability. The V-12 cars are available by customer-order only; expect four to six weeks delivery time.
Your choice: crazy fast or totally insane
With its new engine, the CL550 has largely closed the performance gap with its AMG counterpart. Where the previous CL550 needed 5.4 seconds to reach 60 mph, the new car zooms to 60 mph in 4.6 seconds. That puts it only 0.2 second behind the new CL63 (0.3 second behind the performance-enhanced version). What this means is that, when you bury the long-travel accelerator, either CL is instantly beamed to the bumper of the car ahead. With doubling or even tripling the speed limit within such easy reach, an onboard defense lawyer might be a worthwhile feature.