While cars today have a lot more features like standard air conditioning, power windows, navigation systems, power seats, air bags, ABS, Traction control etc, they don't have any better mileage and in many cases get worse mileage than they did twenty years ago. What happened? Well all those fancy new features we have in all of our cars add weight. Each individual one doesn't add much but it all adds up. Cars also meet higher safety and emissions requirements and they are bigger - a lot bigger. You rarely find cars as small and light as a CRX on American roads today.
It should come as no surprise to drivers that cars don't go as far on a gallon of gas as they did previously. They buy larger and heavier vehicles and so manufacturers adjust to meet customer demand. If buyers today actually go out and buy cars like Fit, Yaris and the upcoming small Ford then manufacturers will build more of them.
[Source: Detroit News]