IN a less-than-persuasive bid to be socially responsible, German automakers (with the exception of Porsche) limit the top speed of their vehicles to 155 mph (250 kilometers per hour). At that — my current velocity in the Mercedes-Benz CLK 63 AMG Cabriolet — 227 feet of chlorophyll-green German countryside streams past every second. In the words of the Bhagavad-Gita, I am become death, destroyer of bugs. The early morning sky is gray, the traffic is light. I have the top down and it's rather windy in the cockpit. Actually, at a buck-55, it's like being inside God's own novelty whistle. FOR THE RECORD: 'Because it's there': In a July 12 review of the Mercedes-Benz CLK63 AMG, the quote "Because it's there" was wrongly attributed to Sir Edmund Hillary as a reason to climb Mt. Everest. It was George Leigh Mallory who said the words about Everest in a New York Times interview in 1923. — No question about it. Fast feels good. No matter what else you may think about high-performance automobiles — that they are reprehensible gas guzzlers, that they are compensations for guys who shower with their shorts on — no one can reasonably dispute speed's pure, gleeful joy. If movement is action, fast feels like you're accomplishing something. Fast is the kinesthetic equivalent of beautiful.
The plastic-wrapped hay bales dotting the swales and valleys look like pearls scattered from a broken strand. Hey! Look at that charming German village never mind. We passed it.
While it's possible to go fast anywhere — a certain Swede in a certain Enzo taught us that — Germany is one of the few places in the world where you can safely and legally maintain a three-digit rate of speed. Just for reference, the highest posted speed limit in the U.S. is 80 mph, recently approved by the Texas Transportation Department for about 400 miles of road in the western part of the state. Go much faster than that and you'll have the opportunity to sample the corrections department's many varieties of armadillo-based cuisine.
Because of the high speeds, the excellent road conditions and — it must be said — the superior skill and courtesy of European drivers, a driving tour of Germany is for passport-holding car guys what the Dublin pub crawl is for jet-setting alcoholics. And yet speed-unlimited stretches of Autobahn are getting fewer and shorter, as traffic densities and Green Party activism continually erode the last Muscle Beach of horsepower. These days, the Autobahn Polizei rely on radar-operated cameras, and if you see a sudden flash out of the corner of your eye, you know you've been caught. Try to smile.
However, on this stretch, the free-fire zone between Stuttgart and Ulm, I can put my foot down and leave it down. The CLK 63's chesty V8 sends an oceanic surge through the car as the speedometer chases the peg 150 kph, 200 kph .
Carmakers find themselves in a peculiar position. Never has there been so great a disconnect between the top speed potential of automobiles and the environment in which they operate. On the American market right now there are 263-hp Hyundais, 400-hp Pontiacs and Cadillacs, and 500-hp Mustangs. Top speed is the outcome of some complex mechanical formulas, involving factors such as horsepower (engine speed times torque), gear ratios and tire size, weight and aerodynamic efficiency. But horsepower is the key ingredient to going fast.
The question is: Where can buyers use all that horseflesh? The answer: nowhere. So why pay for it? In Hillary's famous words: Because it's there.
A case in point is AMG — Mercedes' in-house performance tuning division — that might as well be called the Ministry of Excess Capacity. For years, the company's job has been to take mainstream Mercs and stuff their noses with fissile material, mightily reinforce the chassis, suspension and brakes, and turn out the ultimate sleepers: cars with race car performance that don't look out of place at the Brentwood Whole Foods.
The CLK 63 AMG Cabriolet, gorgeously provisioned with rich wood veneers, luxury-luggage leather and polished brightwork, follows this recipe exactly. This year, for the first time, AMG is building its own engines from scratch, rather than modifying stock Mercedes engines. The 6.2-liter V8 under the sloping hood is a huge gleaming aluminum reactor armed with a multisyllabic array of engine-building technologies — lightweight and reinforced, closed-deck crankcase, low-friction cylinder linings, lightweight valve train with bucket tappets, variable valve timing and variable intake snorkels. What it adds up to is a big, honking, 475-hp V8 with the free-revving character of a turbocharged four-cylinder. This engine delivers lunging, who-hit-me midrange torque (465 pound-feet at 5,000 rpm) and just keeps pulling to its 7,200 rpm redline (and slightly beyond, to tell the truth). Zero to 62 mph (100 kph) goes by in a godless and raunchy 4.7 seconds.
Downstream of the V8 is Mercedes' perfect, smarter-than-thou seven-speed automatic transmission and beyond that a rear axle with a sky-high 2.65:1 gear ratio. Put it all together and — free of electronic interventions — this would be a solid 190-mph car.
But it's not. Pulling onto the Autobahn from — what else, a gas station — I mat the throttle. A meaty and invisible German hand swats me between the shoulder blades, and the car shudders a little. First gear, second gear the car goes like the passions of hell are on its tail. In about 30 seconds or so I'm approaching the 155 mph barrier. The car leans into the air. The tires hiss. The twin exhausts cackle with the sound of high-priced premium benzin catalyzed at a rate of a liter per minute. There's so much engine left to go.
Then the car touches the electronic speed limiter. Suddenly all the tension in the car dissipates with a feeling like detumescence. BBRRRRrrrrrrr The gearbox jumps into the super-tall seventh gear, the rpm sink back to about 3,700 rpm, and I find myself loafing along — puttering, really — hamstrung by a functional impasse.
Now, I'm still going 155 mph, which if you ask the California Highway Patrol is pretty fast. But I feel as if the car has taken a nap. I'm just cruising, driving with one hand and fiddling with the sound system amid the flying acreage.
The bottom line is this: Here in the late stages of internal-combustion technology, horsepower is relatively easy to come by. And as long as car buyers use horsepower as a guide to choose good car from bad — more equaling better — carmakers will supply the ponies. But, clearly, there comes a point when more horsepower is pointless vanity, and I wonder if Never mind. We passed it.
Contact automotive critic Dan Neil at firstname.lastname@example.org.
2006 Mercedes CLK 63 AMG Cabriolet
Base price: $84,500 (est.)
Price, as tested: $92,000 (est.)
Powertrain: DOHC 6.2-liter, 32-valve V8, with variable valve timing and variable intake geometry; seven-speed, three-mode automatic transmission; rear-wheel drive
Horsepower: 475 at 6,800 rpm
Torque: 465 pound-feet at 5,000 rpm
Curb weight: 4,150 pounds
0-60 mph: 4.7 seconds
Wheelbase: 106.9 inches
Overall length: 183.1 inches
EPA fuel economy: 14 miles per gallon city, 20 mpg highway (est.)