Mercedes CLK 63 AMG Cabriolet Review

The Mercedes CLK 63 AMG Cabriolet is like a woman with large, perfectly shaped breasts. No matter how much you try to talk about her other qualities, your attention keeps returning to one thing: the engine’s enormous peak output. The CLK holsters AMG’s first purpose-built powerplant, a normally aspirated mill good for 475 horsepower (507 in its less restricted sibilings). As usual, it’s assembled in Affalterbach by one satanic mechanic, whose name is stamped on a plate affixed to the engine block. In another nod to heritage, the “63” represents the engine’s displacement rounded up from 6.2-liters; homage to the legendary 300 SEL 6.3 produced by Mercedes-Benz from 1968-1972. That’s some heavy heritage.

In fact, the 63 is the highest output engine ever offered in a U.S. CLK (Europe is blessed with the blindingly bonkers 600hp CLK DTM). Prior to 2007, the CLK 55 AMG was the King of The Hill for this body style, serving well-heeled enthusiasts with 362 horsepower and 376 lb.-ft. of torque. Now? AMG's 63 continues the German horspower wars. You see? We’re back to those 475 horses. Oh, and 465 ft-lbs. of twist @ 5200 rpm.

All this power foretells gargantuan performance. In this, the CLK 63 does not disappoint. Mercedes estimates the 3960 lbs. CLK AMG ragtop will hit sixty miles per hour from rest in 4.5 seconds. The soundtrack accompanying this feat lies somewhere between “Days of Thunder” and “Grand Prix”: raspy and guttural, fierce and ferocious. Tether that glorious noise to the CLK’s gut-punching acceleration and, well, trying to recreate that factory stat is an altogether pleasing, entirely addictive experience. You can get into a great deal some serious trouble with this package.

And feel smug doing so. Beefy, heavily bolstered seats slathered with premium quality leather coupled with a thick, perfectly shaped steering wheel (sporting the requisite overly large paddle shifters) make it so. As does the ride quality, which maintains Merc’s plush bump suppression despite sitting on AMG’s 18” wheels shod with super wide rubber (225/40 at the front and 255/35 at the rear). The CLK 63 also delivers epic retardation and stupefying levels of adhesion. Only fuel economy– 13/20 miles per gallon– spoils the fun. Social responsibility aside, that’s roughly 200 miles between refills.

The problems begin with a price tag that leaves little change from $100,000. That’s a lot of wedge for a vehicle that begins life as the CLK 350. More to the point, rather than struggling to change water into wine, you could use your 100 large to buy a prestigious, purpose-built sports car. Although I’d miss the rumble and roar of the 63’s V8 (see?), I can more easily imagine a full-on, six-cylinder Porsche 911 in my garage than a CLK 63.

To make matters worse, the 2007 Mercedes CLK 550 coupe is the better car for $35k less. Its 5.5-liter V8 puts out 382hp and 391 lb.-ft. of torque. With 240 less pounds and a stiffer body shell, the CLK 550 is still plenty potent. Interior color choices are more plentiful. The seats are easier for entry and exit and softer on the bottom. The CLK 550’s soundtrack is equally appealing (it’s a dead ringer for Mustang in “Bullitt”). You even get the oversized paddle shifters and seven-speed transmission.

While we’re at it, the CLK 63’s new, normally aspirated V8 doesn’t leapfrog AMG’s latest 5.5-liter supercharged V8, which pumps-out 516 ft.-lbs. of torque for a wide variety of models (E55, CLS55, S55). Unless you struggle to drive the 55 smoothly from rest or require slightly higher high end performance, the 63 is an expensive extravagance. If you want an AMG-tweaked Merc to overwhelm the tires and assault your neighborhood with clouds of expensive tire smoke and leering power slides, the 63 variants aren’t likely to get your hoonage juices flowing.

I’m a big fan of AMG products; I’ve owned eight so far. From a practiced pistonhead’s perspective, the in-house tuner’s greatest limitation is Mercedes itself. When Mercedes releases an SL550, AMG does the SL55; the CL600 is countered by the CL65; the E550 is met by the E63 and so on. AMG is not advancing the art of high performance automobiles, only taking existing technology to more expensive and extreme levels.

In fact, AMG seems to have hit a plateau. While the CLK 63 and its equally engined siblings offer 23% more mind-blowing torque and 31% more hp than the 55’s, the 63 is not significantly better– in spite of the significantly higher price and swooning depreciation. I’d love to see AMG kick out the jams and build a purpose built, light weight performance automobile. Something that allows its drivers to focus their minds on something other than sheer engine grunt. If Mercedes wants to keep abreast of performance trends, it’s the way to go.