MERC 11 CL Class is a powerhouse of technology

At the risk of stating the obvious, Mercedes-Benz is not a new company. The firm literally invented the automobile—125 years ago next spring—and it has spent a lot of time reminding us of that fact, making hay of every corporate anniversary to come down the pike. Much of this gets written off by pundits as tasteful self-promotion, the kind of throwaway PR that smart brands do in their sleep. But as the 2011 Mercedes-Benz CL recently reminded us, when you're building cars, experience matters. And no one has been building big, expensive luxury cars longer than Stuttgart.

The costly, house-size '11 CL Class is a powerhouse of technology and comfort, one of the most well-rounded cars in the world. Gifted with a mild redesign and efficient new engines for 2011, the CL550 4MATIC and its hot-rod sibling, the CL63 AMG, are two of the most capable and cosseting cars money can buy. In the search for fuel economy, Mercedes ditched the old 550's and 63's large, naturally aspirated V8s in favor of a pair of small twin-turbo eights. Along with a few new safety features, those engines breathe new life into the CL's worthy bones.

The Specs

Because the '11 CL's cosmetic updates are relatively minor—a tweaked grille here, a pair of massaged taillights there and not much else—the powertrain changes are the big story.

A word about the engines being replaced: The previous CL550's naturally-aspirated 382-hp, 5.5-liter V8 was a silky wonder of an engine, a quiet and unobtrusive speed grenade that made its living as a mechanical wallflower. The previous CL63, on the other hand, was powered by something akin to a NASCAR stocker mad drunk on hefeweizen—a bloodthirsty 518-hp, 6.2-liter V8 that specialized in linear power, knife-edged throttle response, and the full-throttle bark of an angry H-bomb. Both were excellent, involving powerplants, though somewhat thirsty by current standards.

The solution lay, as it usually does these days, in turbocharging—smaller displacement, greater volumetric efficiency and the possibility of better fuel economy, all with no decrease in power. The CL550's new mill, known internally as M278, is a 4.6-liter, 429-hp V8 fitted with two turbos and direct fuel injection. It is 12 percent more powerful than the engine it replaces, despite being 20 percent smaller in displacement. At 516 lb-ft at 1800 rpm, it offers a staggering 32 percent more torque; 60 mph arrives in 4.8 seconds, 0.6 second quicker than the old 550, according to Mercedes. And while official EPA numbers haven't been released, the engine is claimed to be over 10 percent more fuel-efficient.

Still, the CL63's new powerplant, dubbed M157, is the real corker. It shares the M278's basic layout (Mercedes claims almost no components are common between the two) but offers 5.5 liters of displacement and a much sharper state of tune. It thunders out 536 hp and 590 lb-ft, the latter of which arrives at a staggeringly low 2000 rpm. (If that number isn't ridiculous enough for you, there's an optional performance package that adds 27 hp, ups the 155-mph speed limiter to 186 mph and drops 0-to-60 acceleration by a tenth, to 4.3 seconds.)

Like the old CL63 engine, the M157 is built by hand in AMG's facility in Affalterbach, Germany; one member of a 50-man assembly team builds it from start to finish, and that individual's signature appears on the engine cover. You know, in case you wanted to find that guy and thank him personally.

The rest of the CL's underpinnings remain relatively unchanged. The old CL550's seven-speed automatic, a unit developed in-house by Mercedes, was retuned and optimized for the M278's personality and torque output. A version of AMG's excellent MCT Speedshift seven-speed automatic lives in the CL63; this transmission first appeared on the 2008 SL63 and is unique in offering both a magnesium housing and a wet clutch in place of a torque converter. Both cars offer driver-selectable sport and economy transmission modes in addition to wheel-mounted paddle shifters.

As if that weren't enough, there are a host of standard safety features—everything from active lane-departure assist to crosswind-compensating active suspension and a frighteningly capable antisleep warning system called Attention Assist—aimed at saving you from your faults, or maybe just your inability to stay conscious on the bothersome Ambien pill that is the modern highway. More on those in a moment.

The Drive

We split our test time between the all-wheel-drive, $114,025 CL550 4MATIC and the $151,125 CL63, thundering over the roads of New York state's scenic Hudson River Valley.

Remember what we said earlier about learning from experience? Big coupes and sedans are what Mercedes-Benz has traditionally done well, bringing the full extent of its technological expertise to bear and coupling it with the engineering latitude afforded by a relatively high price tag. The '11 CL is no exception.

It's best to think of this car as an indulgent two-door version of the company's S-class sedan: one built for an audience where price matters, but only a little. Like the S-class, the CL boasts an interior full of French seams, adjustable ambient nighttime lighting and tightly fitted panels. Switches and latches clunk home with the same kind of reassuring thunk you get from a household circuit breaker. The doors shut like the boiler on a steam locomotive, a hollow whock that would echo throughout the car if it weren't stuffed with the hides of countless unfortunate cattle. The front seats are comfortable, the back seats impossibly roomy; and all four windows roll down, leaving only the pretty, pillarless curve of the car's arched roof.

The CL drives much like its predecessor—it's a wide, heavy and fast car, one that shrinks distance and downplays speed. Both engines offer up impressive response and only the slightest hint of turbo lag. The CL550's V8 is hushed and quiet, the CL63's unit loud and barking, like a dog with lungs the size of the Chrysler Building. Tiny jabs at either engine's throttle are capable of launching you into the next time zone. The 550 is quick and supple, the 63 quicker and more agile. Everything is distant and well-damped, as if Stuttgart feels that drivers should be informed but not care too much about what happens beneath all that paint and leather. Few two-door cars offer the CL's kind of refinement and capability, and most of them are expensive enough to make the Mercedes look cheap.

Impressive though that is, it pales in comparison to what the CL's assorted electronic black boxes cook up. The two most impressive features are also the newest: Adaptive Blind Spot Assist uses radar sensors and a host of chassis inputs to warn you, via a flashing light in the mirror and a tone in your ear, if you try to merge into a car in your blind spot. (Ignore the system and merge anyway, and the car will selectively brake a wheel or wheels in order to steer you away from the offending vehicle.) Adaptive Lane-Keeping Assist is a version of the same idea, one that uses subtle steering-wheel vibrations to warn you if you cross lane lines without turn-signal activation or significant steering input. Ignore the warning and the car will gently guide you back into your lane. Although these systems sound complex and futuristic, they fade into the background in everyday driving.

The Bottom Line

Mercedes-Benz famously believes that its cars have no competition; the company's public-relations representatives often use research data to argue that people simply do not cross-shop a Mercedes with anything else. While we have a hard time believing that this notion applies to some of the firm's more inexpensive machines, the CL, regardless of specification, instills no doubt. Have a fat wallet and want a fast, comfortable, and adult German coupe? This is the best you're going to get.