In this article, Miller & Chevalier lawyers Adam Feinberg, George Hani, and Andrew Howlett and Ryan, LLC President of U.S. Operations Damon Chronis, Principal David Pustejovsky, and Director Brian Browdy discuss Rev. Rul. 2018-2, 2018-2 IRB 277. The authors argue that Rev. Rul. 2018-2 incorrectly assumes that a substance, specifically the butane found in gasoline-butane mixtures, cannot be both a taxable fuel and an alternative fuel for purposes of the alternative fuel mixture credit. The authors discuss the petroleum industry and the Treasury Department's classification of butane as a liquefied petroleum gas (LPG), making it eligible for the alternative fuel mixture credit. "Under the plain language of the statute, butane is an alternative fuel. Rev. Rul. 2018-2 fails to address this fundamental point," the authors wrote. The authors also address the IRS's previous determinations that a substance can be both a taxable fuel and a credit-qualifying fuel. The authors note that the Revenue Ruling "does not consider that, even assuming the IRS is correct that butane is a taxable fuel, it simultaneously can be an alternative fuel. The revenue ruling also fails to explain the basis for its apparent position that butane is a taxable fuel even before it is mixed with gasoline. No matter how these issues are resolved, one truth remains: Butane is an LPG and thus an alternative fuel under the statute."