Increasing the gas mileage performance of your automobile is a great way to reduce your costs, keep your car in top shape, and fill up at the gas station less frequently.
You don't need to buy a new hybrid vehicle to get great gas mileage, just follow a few simple tips and you can improve your gas mileage.
Steps
Change the oil as required. Stop missing your oil changes! You should change your car's oil as often as recommended in your owner's manual. Some cars this is every 3,000 miles, others it may be as high as 10,000 miles. As your car gets older, you should increase the frequency of your oil changes. This will help keep your car in top shape.
Get a Tuneup. A car engine tuneup including spark plug changes and common fluid changes will help keep your car running smoothly and help increase your gas mileage.
Change Your Air Filter. A dirty air filter will cause the engine to not use the right balance of air and fuel and will cause problems which will decrease your gas mileage.
Check Your Tires. Keep your tires properly infated and aligned, doing so can save you up to 5% on fuel efficiency.
Tips and Tactics
Roll Down Your Windows. This summer, try to roll down your windows more often than you use your Air Conditioning. This will increase your gas mileage.
Stop Flooring It! When you enter the freeway or need to pass someone, don't floor the gas pedal! This just wastes gas, try to make a more fluid acceleration, this will allow your engine to keep up and not waste as much fuel.
Remove excess weight from the trunk. An extra 100 pounds in the trunk can reduce a typical car’s fuel economy by up to two percent.
Avoid packing items on top of your car. A loaded roof rack or carrier creates wind resistance and can decrease fuel economy by five percent.
Use overdrive gears and cruise control when appropriate. They improve the fuel economy of your car when you’re driving on a highway.

Drive the Speed Limit. While each vehicle reaches its optimal fuel economy at a different speed (or range of speeds), gas mileage usually decreases rapidly at speeds above 60 mph.
As a rule of thumb, you can assume that each 5 mph you drive over 60 mph is like paying an additional $0.20 per gallon for gas.

