Friday Fuel Economy: Don’t Top Off

Reader Contribution by Staff

One of the best ways to save money on gas and improve your fuel economy is to not buy gas you don’t need, or can’t even use for that matter. The easiest ways to do that is to not top off your tank.

It’s a bad habit for many people — after the pump shuts off automatically they think they can squeeze more gas in their tanks or they want to get the cost to a round number. But the truth is the nozzle knows when to stop. Trust the nozzle. Here’s why:

  • Most gas stations’ nozzles have sensors that shut off the fill up when the sensor is covered with gas. Anything you pump after that either goes back into the station’s tanks or will spill out for the next person who uses the pump. All that extra gas does not end up in your tank. And excessive topping off could damage the pump’s sensors, which will lead to more gas being pumped than is necessary, which leads to more waste and emissions. It’s a vicious cycle.
  • When you spill gas from overfilling or leave gas to squirt out on the next person in line, that creates vapors that are harmful to breathe and contribute to air pollution.
  • Your car’s gas tank needs wiggle room because gas expands as it warms. Too much gas in your tank could damage your car’s vapor collection system and cause your car to run sluggishly and produce more emissions than it normally would.

John Rockhold is a green car enthusiast and Contributing Editor for MOTHER EARTH NEWS.

Need Help? Call 1-800-234-3368