Wisconsin Statutes Police Regulations (Ch. 163 to 177) § 168.04. Standards

(2)(a) Except as provided in par. (b), the rules required under sub. (1) shall prohibit gasoline, automotive gasoline, gasoline-alcohol fuel blends, and reformulated gasoline, as defined in s. 285.37(1), beginning on August 1, 2004, from containing more than 0.5 percent, by volume, of methyl tertiary-butyl ether.

(b) The rules required under sub. (1) shall not prohibit racing fuel used at racing events or in preparation for racing events from containing any amount of methyl tertiary-butyl ether.

(4)(a) In this subsection, “gasoline-ethanol fuel blend” includes such a fuel blend for both automotive and nonautomotive uses.

(b) Except as provided under par. (c), compliance with the requirements, established by the department by rule under sub. (1), of ASTM D4814-17 or the most current version of testing methods adopted by the department may be demonstrated by testing a gasoline-ethanol fuel blend or testing the gasoline base stock from which the gasoline-ethanol fuel blend is produced.

(c) The department may promulgate rules that require that a gasoline-ethanol fuel blend and the gasoline base stock from which the gasoline-ethanol fuel blend is produced meet the requirements of ASTM D4814-17, or the most current version of testing methods adopted by the department. A rule promulgated under this paragraph may not take effect sooner than July 1, 2019.