There's no magic number when it comes to good gas mileage, but generally speaking, anything over 30mpg is considered good. Of course, this varies depending on the type of vehicle you're driving. A small economy car is going to get better gas mileage than a large SUV, for example. But no matter what kind of car you're driving, there are ways to improve your gas mileage. By following some simple tips like keeping your tires inflated and avoiding excessive idling, you can help stretch your gas budget a little further. So next time you're at the pump, take a moment to calculate your mpg. If you're getting good gas mileage, give yourself a pat on the back. If not, there's always room