The tax imposed under this act shall be not less than:
(1) On motor-vehicle fuels other than E85 fuels, $.24 per gallon, or fraction thereof;
(2) on special fuels, $.26 per gallon, or fraction thereof;
(3) on LP-gas, other than compressed natural gas and liquefied natural gas, $.23 per gallon, or fraction thereof;
(4) on E85 fuels, $.17 per gallon, or fraction thereof;
(5) on compressed natural gas, $.24 per gallon, or fraction thereof; and
(6) on liquefied natural gas, $.26 per gallon, or fraction thereof.