Saving gas has to be done from many angles. When most angles are covered, then the most savings will be seen in gas consumption and yearly gas bill. Just like how a tree is not chopped down with 1 swing, but with many. Saving gas also has to be done in chops, cuts, and reductions.
Chop 1 - When the car is parked
Take care of things before you even get on the road.
Plan your trip. approx. $90 per year savings
The time and gas wasted overlapping a route or making multiple stops will really affect your wallet. It is best to plan out your trip. Head to the grocery story, the bank, hair parlor, all in one trip.
Another part of planning your trip is anticipating traffic. In some parts of the city, 15 minutes can change the road completely. It can change it from a pleasant smooth flowing road into a congested cumbersome slug trail. Traffic stops your car from being in motion, that will waste gas.
Maintain your car approx. $250 per year savings
Changing your air filter every 12,000 miles, and your oil at the appropriate time will keep your car in peek condition. Your car gets power from the air it pulls in as well as the gas that is burnt. This means the air filter is a key component. A boost in speed and power, and fuel economy can immediately be seen from an air filter change.
Check your tire pressure. Having tires that are properly inflated can save you approximately 90$ per year off a 3,000 gas bill. Get rid of extra weight that you might be carrying in your car. This could be a third row, a box in the trunk or something sitting in the back seat that you don't need. The more weight your car has to pull around, the more fuel it will require to do so.
Improve aerodynamics of your car. Roof racks, flags and any other objects can mess up your car's aerodynamics. You never want your car fighting with the wind.
So if it has a big fight, more gas is being used.
Alternative Transportation
Public transportation can be an alternative to high fuel costs. If you have two cars, take the most fuel efficient one to work. Carpool if possible, with people that live close by.
Using the these tips can save you an average of $200-500 on your fuel costs. Making these changes is well worth it. Look how much money is saved, just by taking care of things while the car is standing still. When you focus on the tips for when your car in motion, you can easily save another 300 dollars from those tips. Especially with highway travel.