While some might decry the phrase “economical sports car” as being an oxymoron, the truth of the matter is many sports cars get better fuel economy (when driven mildly) than some economy cars. In fact, there are a number of sports cars that routinely return in excess of 25 miles per gallon on the highway and are capable of returning 20 miles per gallon combined.
Combining a small displacement engine with a lightweight body is a perfect recipe for exceptional fuel economy. It also just so happens to be the perfect recipe for terrific handling. That one can have a fun to drive auto and simultaneously get good fuel economy is the automotive equivalent of having cake and eating it too.
Or, in this case, having a sports car and driving it too.
There are other engineering aspects that both serve to make a car more fun to drive and improve its fuel economy. Turbocharging for example, basically recycles the flow of gases that would otherwise escape out of the tailpipe and uses it to pressurize the intake charge, thus enabling a smaller engine to do more work. This has the effect of making a car accelerate more quickly, while using less fuel. Similarly, fuel injection systems can be optimized to make fuel burn more completely. Variable intake and exhaust valves also improve the efficiency of an engine. All of these devices, ostensibly created to improve performance, also just happen to save fuel.