This document contains final regulations relating to the taxes on gasoline and diesel fuel. This document also removes obsolete excise tax regulations. The regulations reflect and implement certain changes made by the Omnibus Budget Reconciliation Act of 1990 and the Omnibus Budget Reconciliation Act of 1993 (the 1993 Act). The regulations affect certain blenders, enterers, industrial users, refiners, terminal operators, and throughputters. The regulations also affect certain persons that sell, buy, or use diesel fuel for a nontaxable use.