(a) [Reserved]

(b) Petroleum diesel test fuel.

(1) The petroleum fuels employed for testing diesel vehicles shall be clean and bright, with pour and cloud points adequate for operability. The petroleum diesel fuel may contain nonmetallic additives as follows: Cetane improver, metal deactivator, antioxidant, dehazer, antirust, pour depressant, dye, dispersant and biocide. Fuels specified for emissions testing are intended to be representative of commercially available in-use fuels.

(2) A diesel fuel designated as “Type 2-D” grade meeting the following specifications, or substantially equivalent specifications approved by the Administrator, must be used for exhaust emission testing:

(3) A diesel fuel designated as “Type 2-D” grade meeting the following specifications, or substantially equivalent specifications approved by the Administrator, must be used for service accumulation:

(4) Other petroleum distillate fuels may be used for testing and service accumulation provided:

(i) They are commercially available; and

(ii) Information, acceptable to the Administrator, is provided to show that only the designated fuel would be used in customer service; and

(iii) Use of a fuel listed under paragraphs (b)(2) and (b)(3) of this section would have a detrimental effect on emissions or durability; and

(iv) Written approval from the Administrator of the fuel specifications is provided prior to the start of testing.

(5) The specification range of the fuels to be used under paragraphs (b)(2), (b)(3) and (b)(4) of this section shall be reported in accordance with §86.094-21(b)(3) or §86.1844-01 as applicable.

(c) Methanol fuel.

(1) Methanol fuel used for exhaust and evaporative emission testing and in service accumulation shall be representative of commercially available methanol fuel and shall consist of at least 50 percent methanol by volume.

(i) Manufacturers shall recommend the methanol fuel to be used for testing and service accumulation.

(ii) The Administrator shall determine the methanol fuel to be used for testing and service accumulation.

(2) Other methanol fuels may be used for testing and service accumulation provided:

(i) They are commercially available; and

(ii) Information, acceptable to the Administrator, is provided to show that only the designated fuel would be used in customer service; and

(iii) Use of a fuel listed under paragraph (c)(1) of this section would have a detrimental effect on emissions or durability; and

(iv) Written approval from the Administrator of the fuel specifications must be provided prior to the start of testing.

(3) The specification range of the fuels to be used under paragraphs (c)(1) and (c)(2) of this section shall be reported in accordance with §86.094-21(b)(3) or §86.1844-01 as applicable.

(d) [Reserved]

(e) Natural gas.

(1) A natural gas fuel meeting the following specifications, or substantially equivalent specifications approved by the Administrator, must be used for exhaust and evaporative emission testing:

(2) The natural gas at ambient conditions must have a distinctive odor potent enough for its presence to be detected down to a concentration in air of not over one-fifth of the lower limit of flammability.

(3) Natural gas representative of commercially available natural gas fuel generally available through retail outlets shall be used in service accumulation for natural gas-fueled vehicles.

(4) A natural gas fuel meeting different specifications may be used for testing and service accumulation if all the following conditions are met:

(i) The alternate test fuel is commercially available.

(ii) Information acceptable to the Administrator is provided to show that only the designated fuel will be used in customer service.

(iii) The Administrator must provide advance written approval for the alternate test fuel.

(f) Liquefied petroleum gas fuel.

(1) Liquefied petroleum gas fuel used for exhaust and evaporative emission testing and in service accumulation shall be commercially available liquefied petroleum gas fuel.

(i) Manufacturers shall recommend the liquefied petroleum gas fuel to be used for testing and service accumulation.

(ii) The Administrator shall determine the liquefied petroleum gas fuel to be used for testing and service accumulation.

(2) Other liquefied petroleum gas fuels may be used for testing and service accumulation provided:

(i) They are commercially available; and

(ii) Information, acceptable to the Administrator, is provided to show that only the designated fuel would be used in customer service; and

(iii) Written approval from the Administrator of the fuel specifications must be provided prior to the start of testing.

(3) The specification range of the fuel to be used under paragraphs (f)(1) and (2) of this section shall be measured in accordance with ASTM D2163 (incorporated by reference in §86.1).

(g) Fuels not meeting the specifications set forth in this section may be used only with the advance approval of the Administrator.

[59 FR 48506, Sept. 21, 1994, as amended at 60 FR 34342, June 30, 1995; 62 FR 47120, Sept. 5, 1997; 63 FR 24448, May 4, 1998; 64 FR 23921, May 4, 1999; 65 FR 8277, Feb. 18, 2000; 79 FR 23694, Apr. 28, 2014; 79 FR 36657, June 30, 2014]