Here's a good example of how the “little things” can really add up. About one in six vehicles on the road has a loose, damaged, or missing gas cap. All those “minor problems” add up to a huge waste of energy each year: the loss of 147 million gallons of gas through evaporation.

Not only does a loose or missing gas cap reduce a vehicle's fuel efficiency by up to two miles per gallon, the evaporating gas pollutes the air. The gas cap is also an important safety component. It prevents the backflow of fuel from the tank if a car is in an accident. So, always make sure your gas cap is re-installed properly after every fill-up. And if you lose the cap or it becomes damaged, replace it immediately.