http://www.msnbc.msn.com/id/21788735/ In this age of Internet chat room “discussions” hypothetical debates abound. One that has surfaced lately asks whether the Nissan GT-R — the supercar introduced to Americans at this week’s Los Angeles Auto Show — can circulate the Nurburgring racetrack in Germany faster than a Porsche 911 Turbo. For car enthusiasts, it’s a question worth debating. The GT-R made its first public appearance this fall at the Tokyo motor show, and buzz has heralded its North American debut this week in Los Angeles, including rumors of remarkable track speeds. While the question of whether a Nissan is faster than a Porsche will be settled as soon as a car magazine gets hold of a GT-R to do with as it pleases, a bigger question remains: Will supercar customers in America write $70,000 checks to a mainstream, high-volume Japanese manufacturer when the GT-R goes on sale here next summer?