It’s time to retire 200 mph as our benchmark sexy top speed. Why? Because the 2013 Mustang Shelby GT500 (above) has a max speed that begins with a “2,” courtesy of the 650-hp V-8. ­Jamal Hameedi, chief engineer of Ford’s Special Vehicle Team, credits the upgrade to Ford’s own Boss 302. “Keeping the Shelby clearly separated from the Boss drove a lot of the power and handling changes,” he says. But I suspect that we really have Chevy to thank, as the 2012 Camaro ZL1 packs a 580-hp V-8 that trumps the old Mustang. Whatever gets the credit, when a production Mustang can run at a quarter of the speed of sound, we need to redefine our threshold of awe.