ORS 319.530: Per-mile road usage charge.

319.530. (1) To compensate this state partially for the use of its highways, an excise tax hereby is imposed at the rate of [34] 46 cents per gallon on the use of fuel in a motor vehicle.

      (2) Except as otherwise provided in subsections (3) to (6) of this section, 100 cubic feet of fuel used or sold in a gaseous state, measured at 14.73 pounds per square inch of pressure at 60 degrees Fahrenheit, is taxable at the same rate as a gallon of liquid fuel.

      (3) 123.57 cubic feet, or 5.66 pounds, of compressed natural gas used or sold in a gaseous state is taxable at the same rate as one gasoline gallon.

      (4) 1.353 gallons, or 5.75 pounds, of liquefied petroleum gas is taxable at the same rate as one gasoline gallon.

      (5) 1.71 gallons, or 6.059 pounds, of liquefied natural gas is taxable at the same rate as one diesel gallon.

      (6) One kilogram of hydrogen is taxable at the same rate as one gasoline gallon.