http://blog.caranddriver.com/how-to-drink-less-fuel-five-tips-for-efficiency-enthusiasts-2/1: Trim the weight of your car. Remove golf clubs, antifreeze, dumbbells, and any other garbage you tote around daily. Moving more weight requires more energy and consumes more fuel. For max mpg, think and run light.
2: Keep your tires properly inflated. It sounds simple because it is. A properly inflated tire not only will last longer, it will reduce the energy necessary to make it roll. Concerning inflation pressures, it’s wise to err on the high side.
3: Maintain your engine. Putting off oil changes can lead to the buildup of sludge. Old spark plugs may not fully ignite fuel. A dirty air filter will reduce an engine’s power output. All of the above lead to less efficient motoring.
4: Drive your car to warm it up. A cold engine runs rich, injecting more fuel than when at normal operating temp. Drive your car cold—just don’t hammer on it. It’ll warm up faster than it does idling, and that fuel will not be wasted on zero miles.
5: Skip gears in town. If you have a manual transmission, try shifting from first to third and then from third to top gear. You don’t need to go through every ratio when accelerating around town. Trust us; this trick will save gas.