26 C.F.R. § 48.4041-0
Applicability of regulations relating to diesel fuel after December 31, 1993
Sections 48.4041-3 through 48.4041-17 do not apply to sales or uses of diesel fuel after December 31, 1993. For rules relating to the diesel fuel tax imposed by section 4041 after that date, see § 48.4082-4.