New Car Reviews

2005 Porsche Boxster vs. 2005 Mercedes-Benz SLK350

Fifty years after the androgynous-looking method-style actor appeared in Rebel without a Cause, James Dean’s taste for speed still resonates in popular culture. We’re wearing his red jacket and his bad attitude whenever we see a sports car today and ask ourselves, “Is this car cool enough, tough enough, fast enough? Would James Dean drive this car?”

The always has had a built-in edge in the James Dean test, because its 1950s-style retro look is meant to recall the Porsche 550 Spyder the actor drove in 1955. The Boxster‘s direct, quick responses have commanded our respect from the first, and its speed has improved markedly in the second-generation car. The Boxster is an authentic sports car, the kind of car Dean would drive.

Other retro-look roadsters have not been so lucky, and the Mercedes-Benz SLK is a case in point. From the beginning, this car has struggled to overcome its concept-car novelty. Now, the second-generation SLK marks a focused effort by Mercedes-Benz finally to establish the SLK as a sports-car franchise. So we had no choice but to put the SLK to the James Dean test.

We brought the Boxster and the SLK together at 1219 North Vine Street in Hollywood, the place where Dean began his last drive on September 30, 1955. Then it was the site of the service shop for Competition Motors, a Porsche and Volkswagen dealership. It was a Friday, and mechanic Rolf Wtherich spent the morning preparing Dean’s Porsche 550 Spyder for a race that Sunday at the airport in Salinas, some 300 miles away near Monterey. These days, the old shop has a derelict Goodyear tire store at one end and a Mexican grocery at the other. There’s a curious faded glamour to the spot, and you can look up Vine Street to the hills and catch a glimpse of the famous sign that proclaims “Hollywood.”

The Boxster and the SLK also have some glamour of their own. The second-generation Boxster has slightly more muscular proportions; it now looks like a genuine statement of style, not just a bite-size fashionista. Meanwhile, the Italianate lines of the current design idiom at Mercedes-Benz have come to the SLK at last, and the car looks provocative in profile, especially in the BMW-like interplay of surfaces in the doors. But once you walk around to the front, it looks as if it’s wearing an SL mask from a costume shop.

Dean and Wtherich left Hollywood in the 550 Spyder (serial number 550-0055) at about 1:45 p.m. and drove on surface streets to Castaic, where U.S. 99 began its climb over the mountains to Bakersfield, and stopped for a milk shake at Tip’s, a local diner.

We drove the choppy concrete of Interstate 5, which overlies the old route into the mountains. Both the Boxster and the SLK ride very well on the freeway, despite compact wheelbase dimensions. As you’d expect, the Mercedes-Benz feels locked into the road, as if it has supernatural stability. The Porsche is livelier, yet it never stings you on broken pavement the way the first-generation Boxster did.

The SLK’s hard top makes long-distance travel a luxurious experience, effectively sealing out the elements while creating an environment quiet enough to appreciate the audio system (the CD player is still in the glove box, though). The Boxster’s new, three-layer soft top makes it almost as quiet, but its audio system doesn’t quite measure up. Both cars have decent cup holders at last, and there’s enough cargo space in the center console and door pockets for your stuff. If only there were more room for people. These cars are still short-coupled and narrow, and efforts to carve out a bit more room for the drivers have been only modestly successful. Thanks to its new tilt-and-telescoping steering wheel (like that of the SLK), the Porsche’s driving position is the more spacious of these two cars.

When Dean came down the steep, four-lane Grapevine grade from the mountains to the floor of the San Joaquin Valley on old U.S. 99, an officer from the California Highway Patrol gave him a ticket, and the CHP still patrols this stretch of highway very intensely. To follow Dean’s route, we continued on U.S. 99 through Bakersfield, then made the exit for California Highway 46 at Famosa. There’s not much out there in the agricultural belt, and Dean ran the 550 Spyder to 100 mph on his way west.

The new 268-hp, 24-valve, 3.5-liter Mercedes-Benz V-6 will take the SLK all the way to 155 mph once the hard top is in place to improve aerodynamics. The combination of the wide power band and a six-speed gearbox also gets the SLK to 100 mph a full second quicker than the Boxster. Just as important, this engine also makes an assertive burble from its twin exhausts, an unprecedented mark of character from a Mercedes V-6.

The Porsche‘s 236-hp, 2.7-liter flat-six zings toward its 7200-rpm redline as if the laws of friction didn’t apply. Because the Boxster is 280 pounds lighter than the SLK, this free-revving engine can nearly overcome the Benz V-6’s 32-hp advantage under full-throttle acceleration, so the Porsche gets to the quarter-mile just 0.3 second behind the SLK. But the Porsche flat-six also has 59 lb-ft of torque less than the Benz’s V-6, and it shows in the Boxster’s sluggish top-gear acceleration, which is 2.9 seconds slow-er than the SLK from 30 mph to 70 mph. With the top in place, the Boxster seems to run into a barrier of wind resistance at 151 mph (8 mph shy of Porsche’s claimed top speed).

As California Highway 46 crosses Interstate 5, it becomes one of the most dangerous highways in the state, as cars attempt to pass trucks on the two-lane road. It was busy even on September 30, 1955, as Dean made his way west at about sunset. At Blackwell’s Corner, Dean saw the Mercedes-Benz 300SL of Lance Reventlow, who later would build a sports car of his own, the Scarab. Dean stopped to chat and ate an apple from the roadside stand (now it sells locally grown almonds and pistachios). Then he drove off toward Paso Robles. He never made it.

The intersection of California Highway 46 and California Highway 41 has been altered long since, but you still can imagine the old Y-style layout, where the roads from Fresno and Bakersfield come together on the way to Paso Robles. As you cross Polonio Pass on the new highway, you can see to your left the old, narrow road that Dean drove.

Dean sped west, with the setting sun almost directly in his eyes as he neared the intersection. Ahead, Donald Turnupseed was traveling east toward Dean and started to turn left toward Fresno onto Highway 41. Turnupseed never saw the low, silver Porsche in the dusky twilight. It was a few minutes before 6:00 p.m.Dean’s Spyder glanced off the left front corner of Turnupseed’s 1950 Ford Tudor at about 60 mph, and the aluminum Porsche crinkled up like tin foil. Wtherich was thrown from the car but survived despite a badly mangled left leg. Dean broke his neck in the impact and died, never regaining consciousness, before the ambulance arrived. Sanford Roth, a photographer doing a story with Dean that day, arrived soon after the crash and took pictures of the accident scene. The photographs reached print just as Rebel without a Cause reached theaters, and a legend was born. There’s a monument to Dean in Cholame, about a mile west of the crash site.

We carried on into Paso Robles, then a small ranch town and now the center of a booming wine industry. In 1955, the racers were traveling to Salinas, but today they go to Laguna Seca Raceway, which was built near Monterey in 1957. Take the back way to Laguna Seca by exiting U.S. 101 at Greenwood, and then drive inland through the vineyards to Carmel Valley Road. For nearly thirty miles, this narrow county road twists among the coastal oaks along the Carmel River (hardly more than a creek, really).

Light and eager, the Porsche Boxster steers through the corners like a roller skate, as always. A 10 percent increase in body stiffness and careful suspension revisions in the second-generation chassis help give this car far more composure than ever before. The Boxster just flies through the corners, and the wide (and soft) rear tires keep the car steady beneath you. When stability control intervenes, it engages gradually. We liked the predictable breakaway of the optional eighteen-inch Michelin Pilot Sports, although the car was so low that we often scraped the plastic splash guards of the Porsche‘s underbelly.

At first, the SLK seems less impressive. You just can’t fight the consequences of the front-mounted engine layout, while the heavy hard top is also packaged high in the chassis. If you try too hard, the SLK feels a little unsettled as it dives toward an apex, and the front end washes out. Once the front tires hook up again, the car tries to pivot. It’s not a happy combination, and stability control is like the hand of Gottlieb Daimler himself shaking you. But if you relax, carry the SLK’s braking nearly to the apex of the corner, and simply maximize the grip from the front tires, the car finds its footing easily. The cornering limits are actually very high, and the broad power band of the V-6 also makes it easy to sustain your speed.

The Boxster and the SLK compare much as they did in their first-generation iterations. The Boxster is light and direct-a machine for driving. The SLK is composed and comfortable-a GT car cleverly cut down to a personal size. What’s surprising is the way the two cars have evolved toward each other. The Boxster now feels more substantial, and a 300-mile tour doesn’t seem like punishment. With no spare tire, the Boxster even offers more luggage space than the SLK. Meanwhile, the Mercedes will take you anywhere on the turnpike, yet you don’t have to feel embarrassed as you follow the BMWs and Porsches toward Carmel Valley Road.

Mercedes has put a lot of effort into the SLK (consider the SLK55!), and we think it finally has the sports-car authenticity it’s needed. The evolution of the Boxster and the SLK shows us again that sports cars command our attention in a way other cars do not. The sports car is a constant value, not a romantic anachronism. It can be stylish and civilized, but it’s only satisfying if it also represents an act of rebellion. James Dean still lives on in popular culture because the spirit of rebellion keeps his story from being dissipated by time, fading memory, and commercialization. It is a worthwhile lesson for any automaker that builds sports cars.

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18 City / 27 Hwy

Horse Power:

240 @ 6400


199 @ 4700