1.  Consider what exactly you need in a car, such as the amount of people you typically haul.  Assessing those needs will help you determine which car meets, without exceeding your actual needs.

2.  Assess what size vehicle you need.  Larger vehicles weigh more than smaller vehicle which means they burn more fuel.  If you do not need a larger vehicle, do not buy one.

3.  Smaller engines require less horsepower which requires less gas.  Choose a four-cylinder vehicle over a six-cylinder for great fuel efficiency.

4.  Do your research on miles-per-gallon statistics.  Compare vehicles in terms of how many miles you will be able to travel for each gallon of gas you buy.

5.  Consider purchasing a Hybrid since they will save you the most gas.  Even though Hybrids are a bit more expensive than a standard vehicle, the amount that you will save in gas will compensate for the price of the car itself.

6.  Diesel-fueled vehicles are approximately fifty percent more fuel efficient that gasoline-fueled cars.  Right now, they are not particularly common in America, but they account for about half of automobile sales in Europe. 

7.  Avoid choosing options that increase the gasoline intake of your car, such as four-wheel drive, automatic and additional weight such as luggage racks.

8.  If possible, buy a new car over a used since a vehicle's miles-per-gallon decreases as its age increases.

9.  Purchase low-resistance tires.  Low-resistance tires means less energy is needed for the car to move, which in turn means less gas is needed.

10.  Avoid stop-and-go drives if possible and avoid speeding.  Both of these driving techniques waste gas.