(a) There is hereby levied and imposed an excise tax of Five and one-half (5 ½ ¢) cents per gallon on the use, within the meanings of the word “use” as defined in this Act, of all special fuels delivered in this State into the fuel supply tank or tanks of motor vehicles. The delivery or placing of special fuel into the fuel supply tank or tanks of motor vehicles for use in whole or in part for power to propel such vehicles on the public highways shall constitute and is hereby declared to be the taxable incidence of this levy.

(b) An excise tax of Five and one-half (5 ½ ¢) cents per gallon is also levied, in consideration of the use of the highways of this State, on the use of all special fuels imported into Oklahoma in the fuel supply tank or tanks of motor vehicles and used to propel said motor vehicles for commercial purposes, public or private, or for transportation for hire or compensation, on the public highways of this State, which tax shall be measured and determined by the number of gallons of such imported special fuels actually used in Oklahoma.