Some simple ways to save gas from Yahoo:
A warm engine is more effective,so string errands together by driving to the farthest destination first, which will get the block heated up, and then working your way home.
On local roads, keep cool by opening the windows, enjoying the breeze, and turning off the gas-draining air-conditioning. At highway speeds, however, driving with the windows down creates drag. So at 40 mph or faster, roll up the windows and put on the AC.
Notice to hoarders: You don't need to lug around a case of oil, a bag of sand, or that box of antique tools you got at the garage sale, right? So empty the trunk-less weight, better mileage.
At the pump, avoid gas rated E15. The E is for ethanol, which has about 30 percent less energy than gasoline and kills mpg. (Ethanol-free gas is rare today; you'll probably have to settle for E10.)
Avoid traffic pinch points when you can. Driving at speed is more fuel efficient than creeping along in low gear.
While at the filling station, inflate your tires properly and check them for uneven wear. And steer clear of those stickier, wider performance tires, which increase road friction and can sap your fuel.