Save Energy

Hybrid cars like the Toyota Prius are some of the most fuel efficient on the market.Car pooling to work reduces the number of cars on the road, saves gas and saves money.Telecommuting just two days a week could save the United States 1.35 billion gallons (5.1 billion liters) of fuel.A four-day workweek, which consists of four 10-hour days instead of five eight-hour days, saves on gas and energy bills while still accomplishing the same amount of work.

Optimal speed

According to the EPA, 60 mph (97 kph) is the optimal speed for fuel efficiency.Alternative fuels like vegetable oils and ethanol (made from corn) enable cars to run on natural renewable sources. Speeding, accelerating and hard braking require your car to overcome inertia, which can deplete fuel efficiency by 33 percent.

Increase your fuel economy

Modifying your driving habits can save you money and increase your fuel economy by up to 47 percent.That 100-pound (45-kilogram) suitcase in your trunk will decrease your fuel economy by 2 percent; eliminating weight from your ride can greatly improve your gas mileage.
Since well-inflated tires have less contact with the road, they encounter less friction. Therefore, the engine doesn't have to work as hard to move the car. -If you want to get even more efficient, you can switch from regular tires to low rolling resistance tires. Low rolling resistance tires are harder than regular tires, so they encounter even less friction. Treehugger.com reports that using low rolling resistance tires can lead to a 6 percent increase in fuel economy [source: Treehugger.com]. There are some downsides to the tires, however. They're a lot harder than regular tires, so your car's ride and handling may suffer. Also, don't run out and buy low rolling resistance tires unless you were planning on replacing your tires anyway. The savings in fuel won't offset the cost of new tires. Wait until you need new tires before getting them. Finally, work with your mechanic or tire shop to find the proper low rolling resistance tires for your car.