Alternative Fuel Tax

Liquefied natural gas (LNG), ethyl alcohol, and methyl alcohol are taxed at a rate of $0.14 per gasoline gallon equivalent (GGE) when used as motor fuel. Compressed natural gas (CNG) and propane used as motor fuel are taxed at a rate of $0.10 per GGE and $0.20 per GGE, respectively. For taxation purposes, the fuels are converted to GGEs as follows:

  • One GGE of LNG is equal to 1.5536 volumetric gallons of LNG
  • One GGE of CNG is equal to 126.67 cubic feet of its natural service delivery line pressure
  • One GGE of propane is equal to 4.24 pounds per gallon of liquid at 60 degrees Fahrenheit
(Reference South Dakota Statutes 10-47B-3 and 10-47B-4)