In the case of liquefied natural gas or propane used as motor fuel, "gallon" means a diesel gallon equivalent as defined by Section 1.8A of this Act. In the case of compressed natural gas used as motor fuel, "gallon" means a gasoline gallon equivalent as defined in Section 1.8B of this Act.
35 ILCS 505/1.8
"Gallon" means, in addition to its ordinary meaning, its equivalent in a capacity of measurement of substance in a gaseous state
Known as the Motor Fuel Tax Law
The act spans §§ 35-505-1 to 35-505-8b (85 sections).
P.A. 100-9, eff. 7-1-17.
Official source: Illinois General Assembly. Reproduced from public-domain Illinois statutes; confirm against the official source for the current text. Not legal advice.