As used in this subchapter:

((1)) The term “octane rating” means the rating of the antiknock characteristics of a grade or type of automotive fuel as determined by dividing by 2 the sum of the research octane number plus the motor octane number, unless another procedure is prescribed under , in which case such term means the rating of such characteristics as determined under the procedure so prescribed.

((2)) The terms “research octane number” and “motor octane number” have the meanings given such terms in the specifications of the American Society for Testing and Materials (ASTM) entitled “Standard Specification for Automotive Spark-Ignition Engine Fuel” designated D4814 (as in effect on ) and, with respect to any grade or type of automotive gasoline, are determined in accordance with test methods set forth in ASTM standard test methods designated D 2699 and D 2700 (as in effect on such date).

((3)) The term “knock” means the combustion of a fuel spontaneously in localized areas of a cylinder of a spark-ignition engine, instead of the combustion of such fuel progressing from the spark.

((4)) The term “automotive fuel retailer” means any person who markets automotive fuel to the general public for ultimate consumption.

((5)) The term “refiner” means any person engaged in the production or importation of automotive fuel.

((6)) The term “automotive fuel” means liquid fuel of a type distributed for use as a fuel in any motor vehicle.

((7)) The term “motor vehicle” means any self-propelled four-wheeled vehicle, of less than 6,000 pounds gross vehicle weight, which is designed primarily for use on public streets, roads, and highways.

((8)) The term “new motor vehicle” means any motor vehicle the equitable or legal title to which has not previously been transferred to an ultimate purchaser.

((9)) The term “ultimate purchaser” means, with respect to any item, the first person who purchases such item for purposes other than resale.

((10)) The term “manufacturer” means any person who imports, manufactures, or assembles motor vehicles for sale.

((11)) The term “automotive fuel requirement” means, with respect to automotive fuel for use in a motor vehicle or a class thereof, imported, manufactured, or assembled by a manufacturer, the minimum automotive fuel rating of such automotive fuel which such manufacturer recommends for the efficient operation of such motor vehicle, or a substantial portion of such class, without knocking.

((12)) The term “model year” means a manufacturer’s annual production period (as determined by the Federal Trade Commission) for motor vehicles or a class of motor vehicles. If a manufacturer has no annual production period, the term “model year” means the calendar year.

((13)) The term “commerce” means any trade, traffic, transportation, exchange, or other commerce—

((A)) between any State and any place outside of such State; or

((B)) which affects any trade, transportation, exchange, or other commerce described in subparagraph (A).

((14)) The term “State” means any State of the United States, the District of Columbia, the Commonwealth of Puerto Rico, the Virgin Islands, American Samoa, Guam, and any other commonwealth, territory, or possession of the United States.

((15)) the  term “person”, for purposes of applying any provision of the Federal Trade Commission Act [ et seq.] with respect to any provision of the subchapter, includes a partnership and a corporation.

((16)) The term “distributor” means any person who receives automotive fuel and distributes such automotive fuel to another person other than the ultimate purchaser.

((17)) The term “automotive fuel rating” means—

((A)) the octane rating of an automotive spark-ignition engine fuel; and

((B)) if provided for by the Federal Trade Commission by rule, the cetane rating of diesel fuel oils; or

((C)) another form of rating determined by the Federal Trade Commission, after consultation with the American Society for Testing and Materials, to be more appropriate to carry out the purposes of this subchapter with respect to the automotive fuel concerned.

((18))

((A)) The term “cetane rating” means a measure, as indicated by a cetane index or cetane number, of the ignition quality of diesel fuel oil and of the influence of the diesel fuel oil on combustion roughness.

((B)) The term “cetane index” and the term “cetane number” have the meanings determined in accordance with the test methods set forth in the American Society for Testing and Materials standard test methods—

((i)) designated D976 or D4737 in the case of cetane index; and

((ii)) designated D613 in the case of cetane number,