Section 1065.725 - High-level ethanol-gasoline blendsFor testing vehicles capable of operating on a high-level ethanol-gasoline blend, create a test fuel as follows:
(a) Add ethanol to an E10 fuel meeting the specifications described in § 1065.710 until the ethanol content of the blended fuel is between 80 and 83 volume %.(b) You may alternatively add ethanol to a gasoline base fuel with no ethanol if you can demonstrate that such a base fuel blended with the proper amount of ethanol would meet all the specifications for E10 test fuel described in § 1065.710 , other than the ethanol content.(c) The ethanol used for blending must be either denatured fuel ethanol meeting the specifications in 40 CFR 1090.270 , or fuel-grade ethanol with no denaturant. Account for the volume of any denaturant when calculating volumetric percentages.(d) The blended test fuel must have a dry vapor pressure equivalent between 41.5 and 45.1 kPa (6.0 and 6.5 psi) when measured using the procedure specified in § 1065.710 . You may add commercial grade butane as needed to meet this specification.79 FR 23811, Apr. 28, 2014, as amended at 85 FR 78468, Dec. 4, 2020