For 2011, that doyenne of decadence, the Mercedes-Benz CL coupe, has undergone a bit of restyling at the front and rear, although the more substantive changes are under the long hood. Both the CL550 and the CL63 AMG have new, smaller V-8 engines (although that’s not reflected in their names). But never fear, masters of the universe. Despite the downsizing, the new engines are significantly more powerful than their predecessors.
The CL550 engine has gone from 5.5 liters to 4.7 liters, but it gains two turbochargers and direct injection. Output jumps by 47 hp to 429 hp, and torque increases by nearly a third, to 516 lb-ft. As before, output flows through a seven-speed automatic transmission to all four wheels. (The CL550 is the only big Mercedes coupe with 4Matic.)
The CL63’s powertrain features even more changes and ushers in a new era for AMG. The old 6.2-liter normally aspirated V-8 gives way to a new twin-turbo, direct-injected 5.5-liter, an update that will eventually come to all of AMG’s “63” models (including the S63, which gets the new engine concurrently with the CL). Standard output is 536 hp and 590 lb-ft of torque, up from 518 hp and 465 lb-ft. Opt for the AMG Performance Package, however, and the engine spins out 563 hp and 664 lb-ft (and a more indulgent top-speed limiter allows 186 mph). So equipped, the CL63’s 0-to-60-mph time is4.3 seconds, per AMG, against 4.4 seconds in standard trim.
The CL63 has AMG’s seven-speed Speedshift transmission, which uses a wet clutch in place of a torque converter. Seen previously in the SL63 and the E63, the gearbox here has a different clutch pack and new software and is better mannered. Not only does it snap off superquick gearchanges and match revs on downshifts, but it now also equals the smoothness of a torque-converter automatic when taking off from a stop.
Speaking of stops, the CL63 incorporates an auto stop/start function-a first for Mercedes (outside of its hybrids). It should give a boost to real-world fuel economy, and indeed, preliminary EPA estimates for the CL63 are 15/21 mpg, significantly better than the 2010 model’s dismal 11/18 rating. (The CL550’s figures improve by 1 mpg both in city and highway driving, to 15/22 mpg.) The auto stop/start function works well, restarting quickly enough so as not to impede takeoff. But it’s strange how the sudden silence at red lights actually calls attention to itself-expect conversation to stop as well. The auto-stop feature works only if the transmission is in Comfort mode (which also makes for earlier upshifts and second-gear starts); in the Sport and Manual modes there is no engine shutoff.
Although the CL63’s twin-turbo 5.5-liter outmuscles its big-block predecessor, don’t expect the sharp staccato bark that we know-and love-from the 6.2-liter-and-Speedshift combo in the E63 and SL63 AMG cars. The CL’s rumble is a much more subtle baritone. The CL550’s 4.7-liter V-8 is quieter, enough that you can sometimes hear the whistle of the turbochargers. With its new engine, the CL550 is now nearly as quick as its AMG counterpart, its factory-measured 0-to-60-mph time having dropped from 5.4 seconds to 4.8. That’s only 0.4 second behind the new CL63, or 0.5 second slower than the performance-enhanced version. What this means is that, when you bury the long-travel accelerator in either CL, you’re instantly beamed to the bumper of the car ahead.
The more muscular V-8s pretty much render the V-12 engines superfluous, but they remain in the lineup. The CL600 retains its twin-turbo 5.5-liter twelve (510 hp, 612 lb-ft). The CL65 AMG’s biturbo 6.0-liter V-12 sees a minor power increase (now 621 hp and 738 lb-ft). Still, the CL65 can only tie the 563-hp CL63’s60-mph sprint, likely due to traction limitations. The V-12 cars are available by special order only.
Besides their new powertrains, the big coupes’ driving experience is little changed. The air-sprung CL550 is nearly as compliant as an S-class. With its standard Active Body Control, the CL63 is a bit stiff-legged over bad pavement, but the upside is iron-fisted body control. The CL63 has essentially no body roll, and for such a heavy machine (some 4800 pounds) it’s also amazingly resistant to understeer.
Inside, the S-class-inspired cabin continues largely unchanged, although the large Comand screen can now be equipped with Mercedes-Benz’s split-view technology, which allows the front-seat passenger to watch a DVD, for instance, while the driver sees the navigation screen. In other technology news, the optional lane-departure and blind-spot warning systems will now brake the wheels on one side to nudge the CL back into its lane if the driver ignores their warnings.
The appearance tweaks and substantially improved powertrains should help keep the big Benz coupes relevant and on the radar of an audience whose stature is undiminished.
On Sale: Now
Price: $114,025/$152,125 (CL550/CL63 AMG, est.)
Engines: 4.7L twin-turbo V-8, 429 hp, 516 lb-ft; 5.5L twin-turbo V-8, 536/563 hp, 590/664 lb-ft
Drive: 4-wheel/rear-wheel (CL550/CL63 AMG)