Feature: Track Stars

Paul Meyers

10/01/2007

Not many people would put the Porsche 911 GT3 and the Mercedes-Benz CLK63 AMG Black Series on the same shopping list. Buyers tend to be marque loyalists at this race-bred level, with decidedly different sensibilities: While a GT3 driver typically expects flat-out performance and few creature comforts, the CLK driver tends to prize athleticism with a modicum of civility.

But we couldn’t help noticing that these two cars have a lot in common: Naturally aspirated engines, rear seats sacrificed to weight reduction programs, limited production numbers and identical claims of dashing from zero-to-60 mph in 4.1 seconds. Although the disparity in power ratings might appear substantial—500 hp for the CLK, 415 hp for the GT3—the Mercedes-Benz has to haul about 900 extra pounds, leaving power-to-weight ratios in a near dead heat. Even top speeds are in the same neighborhood, the GT3 topping out at 193 mph and the CLK at 186 mph.

With so many similarities, are these two track-oriented cars really that different? The answer is yes. And no.

When driven back-to-back along the winding pavement of Latigo Canyon Road in Malibu, Calif., both the Porsche and the Mercedes-Benz remain true to expected form. The GT3 makes no pretense at comfort or luxury. "You have to understand that the GT3 is about 90 percent of the GT3 Cup car that I race on a regular basis," says Patrick Long, Porsche’s North American factory driver. "It is the same animal on the road and on the track. It’s not the smoothest or the quietest car on the road, but every car has a give-and-take with comfort and performance."

Dialing in sport modes for the suspension and engine simply requires the driver to press two buttons on the center console—one for tightened suspension and another for increased engine output—only enhancing the car’s road-carving capability. Hairpin turns are conquered with remarkable ease as the sport buttons glow yellow, and the additional 14 hp and 11 ft lbs of torque—though seemingly negligible—is noticeable in every thrust of the throttle. Even the exhaust note bellowing from the dual pipes drops an octave. Extracting this level of performance requires certain trade-offs: The heavy clutch requires more effort than other 911 models, the short throws of 6-speed shifter lack finesse and the car has a choppy ride, even on relatively smooth pavement.

The CLK63 Black Series—an AMG special—offers a less raucous cabin environment. The exhaust note’s burble and bark can still be heard, but the compartment doesn’t shake and hum like it does in the GT3.

Unlike the GT3’s one-size-fits-all manual transmission, the CLK’s AMG Speedshift transmission has three modes: Manual, Sport, and Comfort. The Manual mode employs F/1-style paddles mounted to the steering wheel, while Sport and Comfort modes offer the option of being fully automated. In Sport mode, the Black Series allows for quicker shifts at higher rpms than in Comfort mode, which, as the name implies, is designed for casual commuting. Sport mode even downshifts automatically, blipping the throttle to match rpms as you brake into corners. Deactivating the CLK’s ASR traction control lends the car a more GT3-like persona—stomping on the throttle from a standstill, spins the rear tires for a full 10 seconds before they grip the road and launch forward.

In comparison, on Malibu’s canyon roads, the CLK’s handling suffers. It’s not as sharp, and the rear tires break loose much sooner under hard acceleration. The CLK still offers strong performance right up to nine-tenths of its performance capabilities, and a more comfortable environment for day-to-day driving.

Essentially, the two are more alike than dissimilar, and choosing between them comes down to an individual’s personal taste. As Geoff Day, director of communications for Mercedes-Benz USA, says: "It’s not about the zero-to-60 [performance], it’s about the experience." For a track car that’s drivable on public roads, the Porsche GT3 ($120,670, price as tested) is the car to own. However, for an automobile that can be used both for the commute and weekend track days, the $136,000 Mercedes-Benz CLK63 AMG Black Series makes a convincing argument. The easy answer: take one of each.

Mercedes-Benz, www.mbusa.com
Porsche Cars North America, www.porsche.com/usa