Sixteen variants of the venerable Porsche 911 were available in North America for the 2014 model year, and the one that tops the pecking order as the quickest, most powerful, and most advanced is the Porsche 911 Turbo S (www.porsche.com). It is a technical and mechanical masterpiece that has a starting price of about $183,000. The car’s 3.8-liter twin-turbo flat-6 engine develops 560 hp and 516 ft lbs of torque at 2,100 rpm. That power enables the 911 Turbo S to rocket from zero to 60 mph in 2.9 seconds. It is equipped with all-wheel drive and a 7-speed PDK automated manual transmission that obsoletes a manual gearbox, which Porsche does not offer as an option. The rear-axle steering and the chassis-, suspension-, and brake-management systems help to domesticate this beast, which seems as at home on the interstate or a canyon road as it does on the racetrack.