Porsche will in January debut its 2017 911 Turbo and 911 Turbo S at the North American International Auto Show in Detroit. The models will be available in both coupe and convertible body styles and are equipped with engines offering 20 horsepower more than before, a sharper design, and enhanced features, the company says. In the United States, the new generation of Porsche 911 Turbo will reach dealers in April 2016. The base manufacturer's suggested retail price, not including the destination…