Consolidate your daily trips and errands - This will save you money by cutting down the times you start your engine, which uses more gas.
Avoid air conditioning when possible - But keep in mind, when driving at higher speeds having your windows down creates drag as well.
Be easy with the throttle! Sudden starts and stops wastes gas!
Clean out the trunk! Extra weight creates extra drag.
Use cruise control when possible--a smooth consistant throttle saves gas as well!
Don't let your vehicle idle too long--if you are expecting a long wait, shut your engine off.
Avoid high speeds! You can improve your gas mileage by up to 15% driving at 55 mph rather than 65 mph.
Servicing Your Vehicle
Proper tire pressure is VERY important! By maintaining the proper tire pressure you can realize up to 10% better gas mileage.
Reduce friction, use high quality or synthetic engine oil
Make sure you are using the correct grade of oil for your engine.
Check your oil, low oil levels can make your engine work harder.
Change your filters, Dirty filters can increase the amount of gas your engine uses by as much as 10%
Have your wheel alignment regularly checked
Keep your engine tuned up properly, this can increase gas mileage by up to 4%