Two dream sport cars - the Nissan 370Z and the Audi TT RS. Together,their engines pack 671 horsepower. The Audi TT RS has a 2.5-liter,turbo-charged gasoline direct-injection engine that provides 340 horsepower and 450 Nm of torque.And with the new 370Z,Nissan is raising the bar on its legendary sport-series. In comparison to the 350Z,the 370Z is smaller and lighter. A new 3.7-liter-V6 engine with 331 horsepower gives the car some real kick. We tested both under freezing conditions.