As we blast across the lonely, undulating terrain of the Southern California desert east of San Diego, in a trio of Flint Gray CLS63 AMGs, it occurs to me that I’m only one misplaced rock away from never seeing home again. As I reflect on past incidents, on debris I’ve hit and tires that’ve blown, I’m reminded that at none of those times was I all the way on the floor with 525 hp underfoot.
But then again, such is the seasoning of life. A little existential Tabasco if you will.
For 2011, the AMG-tuned CLS retains its “63” designation, even though it doesn’t retain the same big 6.2-liter V8 as before. Rather, like other V8s in the AMG range, this 63’s engine displacement has shrunk by 0.7 liters to 5.5. And like the others, it also picked up two turbochargers along the way.
By the numbers, this engine’s horsepower and torque curves are intimately intertwined, soul mates of applied physics—peak power of 525 hp at just 5250 rpm, and a walloping 516 lb-ft dollop of max torque that starts at 1750 rpm and flatlines to 5000. The two graphs overlap in such a way that the CLS63 is never really at a loss for acceleration. It just flat-out hauls ass at basically any engine speed beyond idle. And as its hurtling 4,100-pound mass crests triple digits, the implications simultaneously become both frightening and maddening.
In addition to making it very fast, the engine also makes the car incredibly communicative if you’ve got an ear to listen. It says things like You vould like to overtake ze car in front? Ja, zis is not a problem.
The turbo V8 is hooked to an iteration of the excellent seven-speed AMG Speedshift MCT gearbox, termed a “sports transmission” by Mercedes-AMG. Unlike a traditional automatic, the MCT loses its torque converter in favor of a compact wet clutch. You can select gears yourself using the wheel-mounted shift paddles; however, put the car in Sport mode and the gearbox will mediate the gears for you with a seeming clairvoyance. It’ll hold gears and downshift on braking almost as though there were wires running from the trans to electrodes inside your skull. In a car this size, it’s an ideal conduit for unleashing the engine’s fury.
So then, to help this thunderbolt-hurling powertrain go somewhat more green—very, very marginally more green—the CLS63 features a new stop/start engine function as standard. Permanently active in the transmission’s Controlled Efficiency (C) mode, it will switch the engine off when the car comes to a complete stop, and fire it back up as you step on the accelerator to motor away. You might expect a delay, but there is none; it just pops on and goes. Stop/start only works in C. In the other drive modes—Sport (S), Sport plus (S+) and Manual (M)—engine management partially suppresses the V8’s cylinders, interrupting ignition and injection under full loads to enable faster gear changes.
The chassis harnesses the CLS63’s ferocious high-tech drive system via AMG’s equally high-tech Ride Control suspension. Engineered to provide the seeming paradox of both a comfortable ride and a more aggressive, sporting one, it uses steel struts at the front axle and air suspension struts at the rear. The gas-filled dampers are electronically controlled and actively adapt to reduce body roll during hard cornering, squat under hard acceleration, or dive on hard braking, so the vehicle is always kept as level and flat as possible through a variety of conditions.
The brakes—they are suitably massive to control such a heavy vehicle with an inherent propensity to building such massive amounts of moving inertia. Perforated, internally ventilated 360mm (14.2-inch) rotors are used all around, with motorsport-derived composite technology at the front. For even greater bite, even larger ceramic-composite rotors are available as an option.
Speaking of mass: To keep weight to a reasonable level, if you want to call two tons and change reasonable, lightweight construction has been employed throughout, like through the use of full aluminum doors that use deep-drawn aluminum panels with extruded sections; they’re reportedly 50 pounds lighter than conventional steel doors. Panels like the hood, front quarter-panels and trunklid are also aluminum constructs, as well as strategic sections of the underlying chassis itself.
For added safety as you careen down your imaginary autobahn, the CLS63 is available with a pair of new driver aid systems, Active Blind Spot Assist and Active Lane Keeping Assist. The first uses short-range radar to monitor the, yes, blind spots in adjacent lanes. If the car comes too close to a vehicle the system detects, it will actually apply braking force to the wheels on the vehicle’s opposite side via the ESP stability program, creating yaw that counteracts the impending collision. Lane Keeping Assist works in a similar way, first warning the driver of lane departure and then intervening with ESP.
If you feel the need for expanded performance, an AMG Performance package is available. Special engine management increases peak power to 557 hp at 5750 rpm, and torque by about 74 lb-ft. This will knock a tenth or two off the zero to 60 time and possibly tilt the Earth’s axis by a degree or so. The Performance package also includes a carbon-fiber engine cover and carbon trunklid spoiler, red-painted brake calipers and an Alcantara-accented steering wheel. There’s also what’s called the AMG Driver’s Package, which includes participation in the AMG Driving Academy and elimination of the 155-mph speed restrictor, allowing access to the CLS63’s actual top speed of 186 mph.
Do you actually need to drive at 186 mph? And can you legally attempt such a feat on public roads in the United States of America? Of course not, and hell no. But that isn’t saying it wouldn’t be nice to have the capability. You know, in case the need should eventually arise. All in all, the CLS63 AMG seems ideal for just such a prospect.
2011 Mercedes-Benz CLS63 AMG
5.5-liter V8, dohc, 32-valve,
Three-link front with anti-dive, multilink rear with anti-squat and anti-dive, coil springs, AMG Ride Control electronically controlled dampers, stabilizer bars
Internally ventilated and perforated composite rotors, ABS, ESP, Brake Assist
Length/Width/Height (in.): 196.7/74.1/55.4
Wheelbase: 113.1 in.
Curb Weight: 4,123 lb
Peak Power: 525 hp @ 5250 rpm
Peak Torque: 516 lb-ft @ 1750 rpm
0-62 mph: 4.4 sec.
Top Speed: 155 mph (limited)