How important are vehicle gas caps?
17 percent of the vehicles on U.S. highways have either misused or missing gas caps, causing 147,000,000 gallons of gas per year to vaporize into the atmosphere. (Source: Service Tech Magazine, Sept. 2000)

Vehicle conditions that cost consumers millions of dollars in wasted fuel:

• Loose or missing gas caps
  
• Underinflated tires
  
• Faulty thermostats
  
• Worn spark plugs
  
• Malfunctioning engine controls
  
• Poor wheel alignment

How do underinflated tires affect fuel efficiency?
Underinflated tires and incorrect wheel alignment can lead to conditions which increase rolling resistance. This is like driving with the parking brake not fully released, it can cost a mile or two per gallon on a car that normally delivers 20 miles per gallon. Correct tire inflation pressure is critical for good fuel economy, safety, maximum tire life and proper vehicle handling performance.

Keep your car in tune:
Keeping up with regular vehicle maintenance can improve gas mileage by an average of 4.1 percent. Results may vary depending on the kind of repair and how well it is performed.

How do dirty air filters affect fuel efficiency?
An air filter clogged with dirt, dust and bugs chokes off the air and creates what is called a "rich" mixture - too much gas being burned for the amount of air, which both wastes gas and causes the engine to lose power. Replacing a clogged air filter can improve gas mileage by as much as 10 percent.

Why should spark plugs be replaced regularly?
A vehicle can have either four, six or eight spark plugs, which fire as many as 3 million times every l,000 miles, resulting in a lot of heat, electrical and chemical erosion. A dirty spark plug causes misfiring and that wastes fuel. They need to be replaced regularly.

Other gas guzzlers include:

• Dirty oil = 1 mile per gallon
  
• Slipping automatic transmission = 1 mile per gallon
  
• Cooling system thermostat that causes the engine to run too cold = 2 miles per gallon

Combining all of these discrepancies into one vehicle and the cost of wasted fuel easily could exceed recent increases in pump prices.

Driving Habits to Improve Fuel Efficiency:

• Avoid quick or 'jackrabbit" starts and stops.
  
• Aggressive driving wastes gas. It can lower your gas mileage by 33 percent on the highway and 5 percent in the city.
  
• Observe the speed limit. Gas mileage decreases rapidly above 60 miles per hour.
  
• Avoid excessive idling. Idling gets 0 miles per gallon.
  
• Use cruise control because it helps you maintain a constant speed limit.
  
• Use overdrive gears because the engine speed goes down saving gas and reducing engine wear.
  
• Avoid carrying unneeded heavy items in your trunk. An extra 100 pounds in the trunk reduces a typical car's fuel economy by 1-2 percent.
  
• Use air vents to circulate air instead of air conditioning.

Preventative Maintenance Tips:
Simple preventative maintenance steps that you can do to conserve energy, protect your investment, improve highway safety and benefit the environment include:

• Regularly changing your oil
  
• Inflating your tires properly
  
• Taking your vehicle for annual brake inspections
  
• Changing the windshield wipers

Whether you do it yourself or visit a professional technician, the Car Care Council recommends regular inspections of the following systems:

• Brakes
  
• Electrical and ignition
  
• Emission control
  
• Fuel
  
• Heating and cooling
  
• Steering and suspension

• Engine performance
  
• Tires
  
• Gauges
  
• Windshield wipers
  
• Horn
  
• Lights
  
• Mirrors
  
• Seat belts
  
• Vehicle's body