The V-12 sounds special from the minute you key up its furiously spinning starter. The engine is always impeccably mannered, so you have to listen to hear its voice, but the sound is perfect, be it the low wuffle at idle or the deep resonance when you really open it up. The latter is an activity we can highly recommend. Jam your foot deep into the accelerator's long travel, and the V-12 thrusts this car forward with eye-widening quickness. The effortless power requires the traction control to maintain decorum in both first and second gears, substantially shortens two-lane passing zones, and helps you reach 60 mph in less than 4.5 seconds. But the engine also has a nice, genteel roll onto the throttle at tip-in that makes for liquid-smooth starts from rest--a rare bit of finesse today, when so many try too hard to make a big first impression.
The V-12's prodigious torque output is too much for the seven-speed gearbox, forc-ing Mercedes to pair it with a mere five-speed, but that matters not a bit. Well, maybe it matters for gas mileage: The CL600 chugs a gallon of premium about every twelve miles in city driving and every nineteen on the highway. The CL550 checks in with a more abstemious 16/24 mpg (estimated), but true Masters of the Universe don't concern themselves with this stuff.
Both gearboxes offer the same instantly available manual shifts: just touch the buttons on the back of the steering-wheel spokes--there's no need to clumsily grasp for a manual mode first. On the other hand, we still find the dainty column stalk for selecting P, R, N, and D to be an unsatisfying solution.
So, if the CL600 trumps the CL550, what about the CL63? Its normally aspirated, big-block V-8 (6.2 liters, not 6.3) pours out 518 hp, which just edges past the CL600's 510 hp. The big V-8, however, musters only 465 lb-ft of torque. (Yes, we recognize the absurdity of that last statement in almost any context other than that of monstrously powerful German mega-cruisers, but 465 lb-ft is a lot less than 612.) And without the big push in the back from a massive amount of torque, the CL63 feels merely fast; it doesn't have the CL600's amazing thrust. Nor does the AMG model's powertrain have an overtly sporty persona that sets it off from the standard cars. Quad exhaust tips notwithstanding, it doesn't sound that much sportier, and despite its 7200-rpm redline, the engine doesn't zing the tach needle across the gauge with addictive verve.
The AMG car does have some special qualities, of course. It has the requisite stylized lower bodywork, a deeper front fascia with hashed openings at its sides, hints of a diffuser under the rear bumper, and darker trim in the grille and around the headlights. Its brake rotors, proudly displayed through the standard (and rather plain-looking) five-spoke wheels or the much cooler dark gray split-spoke optional wheels (both twenty inches), are an impressive 15.4 inches in diameter at the front, 13.7 inches at the rear. The CL63 also has slightly firmer programming for its Active Body Control (ABC), but in all three models we drove, the really noticeable difference is between the comfort and the sport settings. The latter is not only sportier but more comfortable as well; it settles the ride over uneven road surfaces and eliminates (Mercedes says) 95 percent of body roll in corners.
Like a good running back, every CL moves with an ease and grace that belies its size. Still, despite the active suspension's steadfast refusal to allow body roll, even the AMG-massaged CL63 is ultimately too big and heavy to be a truly sporting machine. And that's why it stands behind the CL600 in the CL pantheon. Lacking the oh-my-god power of the 6.0-liter--which we know from the previous CL65 and the current S65--the CL63 doesn't make much sense. Why have the sport model when the CL600 is quicker and more luxurious?
Yes, we recognize that there are price differences among the three coupes we drove. Although exact figures weren't set at press time, the 550 should start at about $100,000, the CL63 at $120,000, and the 600 at $130,000 (with every option as standard). Those differences aren't inconsequential, but buyers at this level aren't exactly budgeting their car payments down to the nickel. With a more sumptuous, full-leather-and-Alcantara interior, all the toys, and loads more power, the 600 is the easy choice over the 550; perhaps surprisingly, it also wins out over the slower and not significantly sportier CL63. Until the new CL65 comes along, the CL600 is the best marriage of "big" and "coupe"--and a fitting ride for those Masters of the Universe.