Keeping with the Porsche theme, consider the Porsche Cayman. There are several engine options to choose from, but even the most powerful Cayman R model delivers 330-horsepower and moves from 0 to 60 miles per hour (0 to 96.6 kilometers per hour) in just 4.6 seconds. The fuel efficiency, you ask? It gives you 20 miles per gallon (8.5 kilometers per liter) in the city and 29 miles per gallon (12.3 kilometers per liter) on the highway. In fact, this 3.4-liter flat-six engine-powered sports car gets better gas mileage than a 5-door Mazda3 Speed. That's right.