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.