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.