Optimize Fuel Economy With A "Green Checkup":

1  Check motor oil. Top off and change oil as necessary with manufacturer-recommended grade, "energy conserving" motor oils. Doing so can improve fuel economy by up to 2 percent, according to the U.S. Environmental Protection Agency. Replacing conventional oils with synthetics may offer even greater fuel economy benefits.	2 Check oil and air filters. Replacing a clogged air filter can improve a vehicle's gas mileage by up to 10 percent, according to the U.S. Department of Energy.
3 Check engine performance. Have engines tuned and replace spark plugs according to the manufacturer's recommended schedule. A single misfiring spark plug can cut fuel economy by up to 4 percent, according to the EPA.	4 Check brakes. Improperly maintained brakes can result in unwanted drag and can have the same effect as driving with a foot on the brake pedal, leading to a dramatic drop in fuel economy.
5 Pay attention to warning lights. Ignoring "Service Engine Soon" or "Check Engine" indicators may result in poor fuel economy and require expensive repairs. For example, a warning light may indicate a faulty oxygen sensor, which can result in a 40 percent decrease in fuel economy.	6 Check tires for wear. Replace worn tires with the manufacturer-recommended size and style. To improve fuel economy, consider low rolling-resistance tires.
7 Check tire inflation pressure. Keeping tires inflated to at least the manufacturer-recommended pressure can improve fuel economy by up to 3 percent, according to the EPA.	8 Check for unnecessary items that add weight to the vehicle. Remove heavy items from your trunk and back seat.
9 Check evaporative emission controls. Poorly operating evaporative emission controls can fail to capture gasoline vapors and recycle them to the fuel tank. This wastes gas and degrades air quality.	10 Check transmission. Properly operating modern transmissions and drive components are critical to vehicle fuel economy performance. Routinely check fluid levels and operation. source: www.nada.org

• Combine Trips
  • Making lots of short trips means you’re driving with your engine cold. And that uses more fuel than making one long trip with an engine that’s warmed up. Try combining your short trips around town as much as possible to optimize your fuel economy.
• Drive Sensibly
  • Aggressive driving (speeding, rapid acceleration and braking) wastes gas. It can lower your gas mileage by 33 percent at highway speeds and by 5 percent around town. Sensible driving is also safer for you and others, so you may save more than just gas money.
    
• Observe the Speed Limit
  • While each vehicle reaches its optimal fuel economy at a different speed (or range of speeds), gas mileage usually decreases rapidly at speeds above 60 mph.
• Remove Excess Weight
  • Avoid keeping unnecessary items in your vehicle, especially heavy ones. An extra 100 pounds in your vehicle could reduce your miles per gallon (mpg) by up to 2%. The reduction is based on the percentage of extra weight relative to the vehicle's weight and affects smaller vehicles more than larger ones.
    
• Avoid Excessive Idling
  • Idling gets 0 mpg. Cars with larger engines typically waste more gas at idle than do cars with smaller engines. If you know you’ll be stopped for a while, it’s actually better to turn off your engine instead of idling.
• Use Cruise Control
  • Using cruise control on the highway helps you maintain a constant speed and, in most cases, will save gas.
• Use Overdrive Gears
  • When you use overdrive gearing, your car's engine speed goes down. This saves gas and reduces engine wear.