26 CFR § 48.4081-8
Taxable fuel; measurement
June 25, 2020
(a) In general. Volumes of taxable fuel may be measured on the basis of actual volumetric gallons or gallons adjusted to 60 degrees Fahrenheit.
(b) Effective date. This section is applicable January 1, 1994.
[66 FR 27597, May 18, 2001]