Fuel economy, according to the Car Care Council, is directly related to vehicle care and driver behavior. Both can have a significant impact on how much motorists pay at the pump.
•Underinflated tires can impact the vehicle's fuel economy. When tires aren't inflated properly, it's similar to driving with the parking brake on and can cost a mile or two per gallon.
•Dirty air filters also can waste gas and cause the engine to lose power. An air filter that is clogged with dirt, dust and bugs chokes off the air and creates a "rich" mixture, which is too much gas being burned for the amount of air. Replacing a clogged air filter can improve gas mileage by as much as 10 percent.
•Worn or dirty spark plugs can cause misfiring, which wastes fuel. Vehicles can have four, six or eight spark plugs that fire as many as three million times every 1,000 miles, resulting in a lot of heat and electrical and chemical erosion. Spark plugs that are replaced per the owner's manual will lead to a better performing vehicle.
•Vehicle gas caps that are damaged, loose or missing altogether waste gas. According to the council, about 17 percent of the vehicles on the road have gas cap problems, causing 147 million gallons of gas to vaporize every year.
•When it comes to driver behavior, the council reminds motorists that aggressive driving can lower gas mileage by as much as 33 percent on the highway and 5 percent on city streets.
•Staying within the speed limit also improves fuel economy. Gas mileage decreases rapidly at speeds above 60 mph.
•Excessive idling wastes gas and is unnecessary. A vehicle needs only one or two minutes to warm up. Motorists should also avoid jack rabbit starts and hard stopping -- both make a car less fuel-efficient. Gradually stepping on the gas and gently applying the brakes will improve mileage.
Although traveling usually involves carrying luggage, motorists should try to limit any extra weight or unneeded items in the trunk. An extra 100 pounds can cut fuel efficiency by 1 or 2 percent.