Okla. Stat. tit. 68, § 68-500.4: Levy of tax

A. A tax is imposed on all gasoline, compressed natural gas,

liquefied natural gas and all diesel fuel used or consumed in this

state as follows:

1. Gasoline, sixteen cents ($0.16) per gallon;

2. Diesel fuel, thirteen cents ($0.13) per gallon;

3. Compressed natural gas, five cents ($0.05) per gasoline

gallons equivalent (gge) until the credit authorized pursuant to the

provisions of paragraph 1 of subsection A of Section 2357.22 of this

title expires. Upon the expiration of the credit authorized

pursuant to the provisions of paragraph 1 of subsection A of Section

2357.22 of this title, the rate of tax imposed upon compressed

natural gas shall be equal to the tax rate imposed on diesel fuel

using gasoline gallons equivalent (gge); and

4. Liquefied natural gas, five cents ($0.05) per diesel gallon

equivalent (dge) until the credit authorized pursuant to the

provisions of paragraph 1 of subsection A of Section 2357.22 of this

title expires. Upon the expiration of the credit authorized

pursuant to the provisions of paragraph 1 of subsection A of Section

2357.22 of this title, the rate of tax imposed upon liquefied

natural gas shall be equal to the tax rate imposed on diesel fuel

using diesel gallon equivalent (dge), which shall be equal to six

and six one-hundredths (6.06) pounds of liquefied natural gas.

B. A tax is imposed on all gasoline, diesel fuel and kerosene

used or consumed in this state for use as fuel to generate power in

aircraft engines or for training, testing or research on aircraft

engines in the amount of eight one-hundredths of one cent ($0.0008)

per gallon. All gasoline, diesel fuel and kerosene sold for use

under this subsection shall not be subject to the excise tax levied

in subsection A of this section.

C. Notwithstanding any exemption provided in Section 500.1 et

seq. of this title, all gasoline used or consumed in this state for

use as fuel for farm tractors or stationary engines and used

exclusively for agricultural purposes shall be subject to a tax in

the amount of two and eight one-hundredths cents ($0.0208) per

gallon. All gasoline sold for use pursuant to this subsection shall

not be subject to the excise tax levied in subsection A of this

section. The term "farm tractor", as used herein, shall include all

tractor-type, motorized farm implements and equipment but shall not

include motor vehicles of the truck-type, pickup truck-type,

automobiles and other motor vehicles required to be registered and

licensed each year under the Oklahoma Vehicle License and

Registration Act.

D. It is the intent of this section to amend, revise,

incorporate and recodify the tax imposed on motor fuel and that the

tax shall be conclusively presumed to be a direct tax and shall be a

direct tax on the retail or ultimate consumer precollected for the

purpose of convenience and facility to the consumer. The levy and

assessment on other persons as specified in this act shall be as

agents of the state for the precollection of the tax. The

provisions of this section shall in no way affect the method of

collecting the tax as provided in this act. The tax imposed by this

section shall be collected and paid at those times, in the manner,

and by those persons specified in this act.