Fuel economy is about maximizing the number of miles your vehicle can travel on a gallon of fuel. The cost of fuel has a major impact on fuel economy. Check out these great fuel economy articles from HowStuffWorks.
I know that the faster I drive my car the more gas it uses. But on the other hand I'll get to my destination in less time. Is there a "sweet spot" on the speedometer that would give me maximum fuel efficiency? And if so is it different for different car models?