“Most motorists don’t realize that it’s the little things that don’t take a lot of time or cost much that can really make a difference when it comes to saving money at the pump,” said Rich White, executive director of the Car Care Council. “Loose or missing gas caps, underinflated tires, worn spark plugs and dirty air filters all contribute to poor fuel economy.”

The Car Care Council offers these gas-saving maintenance and driving tips.

* Secure your vehicle’s gas cap. About 17 percent of the vehicles on the road have damaged or loose gas caps or are missing gas caps altogether, causing 147 million gallons of gas to vaporize every year.

* Keep tires properly inflated. Driving on underinflated tires is like driving with the parking brake on and can cost you a mile or two per gallon.

* Replace worn spark plugs regularly. A vehicle’s spark plugs can fire as many as 3 million times every 1,000 miles. A dirty spark plug causes misfiring, which wastes fuel.

* Change dirty air filters. If the air filter gets clogged and chokes off the air, it creates a mixture that’s too “rich” in gas, which causes the engine to lose power. Replacing a clogged air filter can improve gas mileage by as much as 10 percent.

* Don’t be an aggressive driver. Aggressive driving can lower gas mileage by as much as 33 percent on the highway and 5 percent on city streets.

* Avoid excessive idling. Sitting idle gets zero miles per gallon. Letting the vehicle warm up for just one to two minutes is sufficient.

* Observe the speed limit. Gas mileage decreases rapidly at speeds above 60 mph. Use cruise control to maintain a constant speed on the highway.

* Do not carry unneeded heavy items in the vehicle. An extra 100 pounds can cut fuel efficiency by 1 percent to 2 percent.