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Don't Top Off Your Gas Tank!

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cartoon image of man overfilling his car's gas tank
  • Do you top off your gas tank and overfill it?

  • When the gas pump nozzle clicks off automatically, do you add a little more gas to round off your dollar sale?

  • Topping off your gas tank is bad for the environment and your wallet.

    Here's why:

cartoon image of gas pump nozzleTopping off the gas tank can result in your paying for gasoline that is fed back into the station's tanks because your gas tank is full. The gas nozzle automatically clicks off when your gas tank is full. In areas of ozone nonattainment, gas station pumps are equipped with vapor recovery systems that feed back gas vapors into their tanks to prevent vapors from escaping into the air and contributing to air pollution. Any additional gas you try to pump into your tank may be drawn into the vapor line and fed back into the station’s storage tanks.

cartoon image of person coughing due to breathing gas vaporsGasoline vapors are harmful to breathe. Gasoline vapors contribute to bad ozone days and are a source of toxic air pollutants such as benzene. Evaporation from the spillage of gas from overfilling can occur, contributing to the air pollution problem. Remember you pay for the gas that evaporates or is spilled on the ground.

cartoon image of carYou need extra room in your gas tank to allow the gasoline to expand. If you top off your tank, the extra gas may evaporate into your vehicle’s vapor collection system. That system may become fouled and will not work properly causing your vehicle to run poorly and have high gas emissions.

cartoon image of woman pumping gasTopping off your gas tank may foul the station's vapor recovery system. Adding more gas after the nozzle has automatically shut off can cause the station's vapor recovery system to operate improperly. This contributes to the air pollution problem and may cause the gas pump to fail to work for the next person.



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