Instrumented Test
Let’s just cut straight to the chase. This deceptively demure execu-coupe weighs more than 4800 pounds and can sprint to 60 mph in four seconds. That would be four seconds flat.
The CL63 AMG enters triple-digit speeds in 8.8 seconds, trips the quarter-mile lights in 12.3 seconds at 121 mph, attains 150 mph in less than 20, and maxes out at 190 mph, whereupon its governor says, “Das ist genug.”
That’s one governor we’re inclined to agree with, particularly on U.S. highways. You might be able to find places where you deem 190 mph to be reasonable and prudent, particularly in this car, but you’re not likely to find anyone wearing a badge who’ll agree with you.
Primal Power
The source of the CL63’s green-light zeal is AMG’s new twin-turbo, 32-valve, direct-injection aluminum V-8. It replaces the naturally aspirated 6.2-liter V-8 last seen in the 2010 model, which made 518 hp and 465 lb-ft of torque. The turbo engine leaves the AMG works in Affalterbach, Germany, with a horsepower rating no lower than 536 (at 5500 rpm) and torque of 590 lb-ft, on tap from 2000 to 4500 rpm.
Formidable, but not quite enough to produce acceleration at the threshold of the supercar gate. That level comes with the $7300 AMG Performance package—our vehicle was so equipped—which alters engine mapping, increases max boost from 14.2 psi to 15.6, and adds a snappy carbon-fiber engine cover. The carbon fiber probably doesn’t contribute much to engine output, but the net of the other two tweaks is 563 hp and 664 lb-ft of torque.
The power comes on with an addictive hydraulic rush, no waiting, and the seven-speed automatic transmission makes the most of it. Using the paddle shifters abets savoring this cornucopia of thrust. The shifts are prompt enough, although not on par with those of dual-clutch boxes. But there’s such a surplus of torque, and the transmission’s responses in pure automatic modes are so seamless, that simply operating in drive is thoroughly satisfying.
We should note that for really serious torque junkies, with really deep pockets, there’s yet another CL in the lineup that might have even more appeal. The CL65 AMG is propelled by a 6.0-liter SOHC 36-valve twin-turbo V-12 developing 621 hp and 738 lb-ft of torque. If that’s not enough, you probably need therapy.
Mass and Dynamics
For all its face-distorting thrust, the CL’s really amazing attribute is how adroitly it handles a sinuous stretch of back road. Transient responses belie the big coupe’s substantial mass, and the word “agile” keeps inserting itself into the driver’s mind, making it hard to believe he’s herding almost 2.5 tons of sophisticated machinery.
Cornering attitudes are remarkably flat, information from the speed-sensitive rack-and-pinion steering system is abundant, and—for all its roll stiffness—the CL never punishes its occupants, even on the wartiest pavement. Credit the Mercedes “Active Body Control” active suspension here, as well as the CL’s standard torque-vectoring feature. Baked into the stability-control system, this electronic torque distributor applies selective braking to the inside rear wheel during hard cornering to enhance turn-in. It’s basically undetectable, but the results are hard to criticize.
