There are few who would have predicted the extent to which Mercedes-AMG has pushed the CLE Coupe. The Mercedes-AMG CLE 646 Spezialanfertigung is the result: a hand-crafted, V8 track weapon on rear-wheel drive that is down some 375 pounds and puts out over 550 pounds of downforce. With a production run of only 30 for the entire world, it is also already sold out.
As the second model in the Mythos Series after the 250-unit PureSpeed, the CLE 646 is ultra-exclusive. Yet it bears little resemblance to its open-top, windshield-less predecessor. This is a road-legal coupe with an unapologetic bent for the racetrack; don’t be fooled by the familiar CLE silhouette into thinking this is just another special edition from AMG.
The 4.0-liter twin-turbo V8 under the hood has been put through extensive work to deliver 637 horsepowerr. Torque peaks at 627 lb-ft between 2,500 and 4,500 rpm. To make the most of it, the engine is fitted with a flat-plane crankshaft for better throttle response and to lower rotating mass. Three cooling circuits and dedicated mapping see the powertrain through high ambient heat and long stints on track. A custom Akrapovič exhaust made of titanium keeps things light and ensures the V8 makes its presence known.
That is where the CLE 646 becomes truly compelling. AMG has done away with the Performance 4MATIC+ all-wheel-drive of the donor vehicle. All 637 horses are channeled to the back wheels, with an electronic limited-slip differential on the rear axle to aid stability and allow for some controlled drifting when conditions permit.
The nine-speed Speedshift TCT automatic has had its Launch Control reworked for the RWD configuration. While there is no official 0-to-60 number from Mercedes-AMG, they will have you know the car can do 0 to 124 mph in 11.4 seconds and hit a top speed of 193.
The idea came from a handful of engineers wanting to see how much driving performance could be wrung from a CLE. What was a prototype became something far more than a set of bolt-ons.
Starting with the CLE 53, AMG has stripped away roughly 375 pounds in the process of hand-building each example at Affalterbach. You won’t find the rear seats or much of the sound deadening here. Comfort has been sacrificed along with the Parktronic and a simplified audio system. In their stead come carbon-fiber door panels, an integrated roll bar and lightweight racing buckets, with six-point harnesses as part of the optional Performance Package.
You won’t confuse the Spezialanfertigung with the rest of the CLEs. The body has been reinforced and put on a diet of carbon fiber for the fenders, hood, roof, diffuser and the like, while the side and rear windows are now polycarbonate. And to cap it off, AMG has added 2.4 inches of width to both the front and rear ends. At the heart of the CLE 646 is a formidable wheel-and-tire setup. The 20-inch forged wheels are 11 inches wide in front and 12 at the back, shod with no less than 305/30 ZR20 up front and 335/30 ZR20 in the rear. According to AMG, these tires make use of technology they have further refined from the Mercedes-AMG One.
The car sits lower as well, with ride height reduced by 0.9 inch ahead and 0.6 inch behind. A two-tone finish of Mojave Silver Magno and Obsidian Black Magno (from the B-pillar on) is standard on all CLE 646s, but it is the AMG crests on the doors that set this limited-run coupe apart.
To put together a steel-spring coilover suspension befitting the CLE 646, AMG has worked with KW Automotive. The dampers are four-way adjustable for high- and low-speed compression and rebound, so the owner has the latitude to tune the chassis to whatever road or circuit he is on.
When it comes to stopping, there is a carbon-ceramic system from AMG with six-piston fixed calipers clamping down on 16.5-inch front rotors; the rears are fitted with 14.2-inch discs and single-piston floating calipers. This arrangement not only lightens unsprung weight but is aided by dedicated cooling for long stints on track.
One might think the CLE 646’s bodywork is all about looking the part, but AMG has an integrated aerodynamic plan in place. It includes underbody aero, fender louvers, a front diffuser and a carbon-fiber rear wing that can be adjusted.
The diffuser has a manual switch for Street or Race. Put it in Race and the inverted-wing profile will force more air under the car to build up front-axle downforce, while the center of the rear wing can be altered to compensate. There is some ingenuity at work below the surface too: longitudinal fins in the flat floor and channels by the headlights speed up airflow out through the fenders. All told, the package will yield in excess of 550 pounds of downforce when the 193-mph top speed is reached.
On a closed course where one might choose to disengage ESP, the traction control offers nine degrees of rear-wheel slip. It is a matter of letting the driver decide how much electronic input is warranted by the tires and conditions, and how close to the edge he wants to push the machine.
That is the way of the CLE 646: strip away what stands between man and car and let the rest do its job.
These are hand-built in Affalterbach in the same vein as the old 300 CE 6.0 “Hammer,” and the 30 units planned for the world were already committed before the public had a chance to see them.
