In the world of fast cars, one second matters. One second typically marks the difference between a Formula 1 pole sitter and the also-rans. It's an eternity in terms of injection, stability control response, or air-bag deployment, and it sifts the fast cars from the very fast ones.
In the case of the Porsche 911, that one second costs $36,500. That's what it takes to upgrade from a 911 Carrera 4S cabriolet (0 to 62 mph in 4.9 seconds) to the Turbo cabrio (0 to 62 mph in 4.0 seconds). Our test car was equipped with a Tiptronic transmission, which shaves another 0.2 second off the 0-to-62-mph sprint. At 3.8 seconds, this comfy, leather-clad ragtop eclipses the awesome GT3 RS by 0.4 second, and even the more-than-twice-as-expensive Lamborghini Murcilago LP640 roadster is only 0.4 second quicker off the mark than the Porsche.
In traffic by the Rhine River on a sunny Sunday morning, a second or two is less significant than is the third-gear exhaust note or the suspension's response to patchwork tarmac. But on the twisties that lead up the Feldberg Mountain from Kronberg, the time it takes to climb from bottom to top is not to be ignored. We lapped that peak in the new 911 Turbo cabriolet until the sun started to set, continually shaving time off the ten-plus-minute budget we started from.
In terms of top speed, the Turbo cabriolet beats the 179-mph C4 softtop by only 14 mph. In terms of midrange grunt, however, the cars are a league apart. Thanks to the overboost feature that is part of the Sport Chrono kit, the turbocharged flat six briefly develops 505 lb-ft of torque instead of 460 lb-ft between 2100 and 4000 rpm. This extra kick in the butt means that fifth-gear acceleration between, say, 50 and 75 mph, is much stronger. It's too bad, though, that when the turbos are on full boost, intake honk and turbo whoosh create a giant sucking sound that assaults your ears. Open-top sports cars are supposed to sound great, not grating.
As you enter high-speed terrain, such concerns subside. The Turbo takes only 12.6 seconds to reach 124 mph, trouncing the Tiptronic-equipped Carrera 4S cabriolet's 20.1 seconds. (A new dual-clutch automatic will replace the outdated five-speed Tiptronic in about a year.) The Porsche is comparatively docile and easy to drive--up to a point. Above 170 mph, the cabriolet struggles to maintain its composure. The steering feels less meaty and more nervous, and it takes white knuckles and a heavy right foot to hold on to the line.
Tipping the scales at 3650 pounds, the open-air 911 Turbo weighs only 155 pounds more than the hardtop because of its lighter unibody, aluminum doors, and composite engine cover with an integrated rear wing. At $137,360, the Turbo cabrio is the most expensive Porsche, but it is by no means the priciest open sports car on the market. It is a great all-around car that makes speed very accessible, even in the rain or snow.
When grouping the car's abilities in order of merit, the steering tops the pyramid, followed closely by the brakes and the chassis. The engine is strong and torquey, but the new transmission can't come soon enough. The ride is OK on smooth surfaces, but over less than perfect blacktop, the cabrio chips and shrugs in an uncouth yet totally silent fashion. The stability is impeccable until you deactivate the electronic controls and release the ghost of oversteer, be it lift-off or throttle-on.
Of course, a Carrera cabriolet would do just fine, and a C4S would be better still. Both are 100 percent 911 and provide 95 percent of the oomph and brio you'll ever need. But if your bank account can stand it, treat yourself to the Turbo. It demonstrates that one second can indeed make a difference in crowning you king of the road.