Even people who shower like water is going out of style can conserve H2O in a survival situation. So treat fuel as if your life depended on it. Make efficiency a daily priority and consider the larger impacts of small choices.
Mountain climbers must burn calories to maintain body temperature, expend extra energy for every pound packed and be aware of the chilling costs of resting too long. The same rules apply to your car, so carry only what is essential, don't run the air-conditioning unless you have to and try to combine many trips into one (extra weight and air-conditioning burn more fuel, as does driving with a cold engine).
Also, mountain climbers are pretty particular about what they put in their tanks, and you should be, too. If possible, you may want to avoid ethanol-containing fuels like E10 or E15; ethanol stores energy less efficiently than gas, so your car must guzzle more to cover the same distance [source: Allen]. That said, don't spring for premium fuel unless you have to. Premium fuel does nothing for a car built to burn regular, but it does generate more emissions and cost you 20 to 40 cents more per gallon [sources: Car Talk; Wiesenfelder].