Here are a few things you can do today to get better fuel mileage from your existing vehicle.
Think "steady and smooth" as you drive and take the long view of the road so you can brake easy. Don't mash the gas when you start up and don't brake hard to stop. Up to a 33% improvement in highway fuel economy can be realized by changing aggressive driving habits-that translates into a savings potential of more than 180 gallons of fuel or $550 per year!*
Drive the Speed Limit
On the highway, you can assume that with each 5 mph you drive over 60 mph your fuel economy drops by 5%. In town, driving at the speed limit will give you more green lights, improve your gas mileage, reduce idling time, and reduce the wear and tear on your brakes. Using the highway example, when you drive 75 mph vs. 55 mph it's like burning an extra gallon of fuel every 100 miles you drive. So, if you drive 10,000 highway miles, your savings could be as much as $300 per year.*
Selectively Use Cruise Control
Edmonds.com states that you can improve your fuel economy by up to 14% by engaging cruise control when appropriate. Using cruise control smoothes out the accelerator input and encourages the driver not to react to every change in traffic. However, it is counterproductive to use cruise control in hilly terrain; it tries to maintain the set speed and will use a lot of extra fuel downshifting and accelerating faster than typical. Using cruise control on 10,000 of the miles you drive in a year could save you nearly $200 and more than 60 gallons of fuel.*
Avoid Excessive Idling
When your vehicle's engine is idling it gets 0 mpg, contributes to air pollution, and causes engine wear. It is more efficient to turn the engine off while you wait and restart the car when your wait is over. The California Energy Commission (CEC) recommends that you shut off your car anytime you are waiting for more than 10 seconds. CEC asserts that an idling vehicle consumes as much as 1 gallon of fuel per hour. Based on the commission's statement that most people idle 5-10 minutes per day, the savings translate into more than $150 per year.*
Follow the Recommended Maintenance
A vehicle that is well maintained operates with greater efficiency and ultimately improves overall vehicle performance and fuel economy. Fouled spark plugs, a dirty air filter, or a clogged fuel filter will have an adverse effect on your fuel economy. Check your vehicle's owner's manual for maintenance recommendations and schedule check-ups accordingly.
Keep Your Tires Properly Inflated
Under-inflated tires require more energy to roll and, consequently, more fuel is consumed. If you keep your tires inflated properly, you can improve your fuel economy by as much as 2.5%.The recommended tire pressure can be found in your owner's manual or on a sticker on the doorjamb of your car, not on the tire itself. Buy a tire-pressure gauge and check your tires monthly. For more info see http://www.eere.energy.gov/afdc/vehicles/fuel_economy_tires_light.html.
Remove Excess Weight
Weight requires energy to move, so carrying around excess weight will negatively affect your fuel economy. Remove unnecessary items including the roof rack when you're not using it. An extra 100 pounds of weight can reduce your fuel economy by up to 2%.
Use the Highest Gear Possible
To improve your fuel economy, drive in the highest gear possible when you are cruising at a steady speed.
Keep Your Car Clean
Keeping your car washed and waxed may reduce drag and improve aerodynamics. Engineer Tom Wagner, Jr. reported to Stretcher.com a 7% improvement in fuel economy during a 1,600-mile road trip as the result of keeping his truck clean. Highly aerodynamic cars may not yield any noticeable improvement, but the cleaner they are the better they look!
Think Before You Open Your Windows
Air conditioning uses fuel. Driving with your windows rolled down while traveling at a high speed increases drag on the vehicle and may cause more fuel consumption than using the air conditioner. If you need it, roll up the windows and turn on the air conditioning when you're driving on the highway. If you are driving at a slow speed, turn off the air conditioner and roll your windows down.
Combine Your Errands into One Efficient Trip
Several short trips, all starting with a cold start, can use twice as much fuel as one trip with several stops and may cause you to travel more miles. Plan your trips efficiently.
Consider Replacing Worn Out Tires with Low Rolling Resistance Tires
Low rolling resistance tires are designed to improve fuel economy by reducing the amount of fuel it takes to push the tire down the road. The tire's inflation pressure, weight, tread design, and materials contribute to how easy the tire rolls down the highway. A 2003 California Energy Commission (CEC) study has estimated a fuel savings of 1.5% to 4.5% from using low rolling resistance tires. If a car's mileage improves from 20 mpg to 21 mpg, simply by using lower rolling resistance tires, its fuel savings are nearly $100 per year.
*Assumptions for calculations: $3.00 per gallon for fuel, 20 miles per gallon before change, and 15,000 miles per year.
Source: U.S. Department of Energy