North Carolina Administrative Code Title 17 — Revenue 17 NCAC 09I .0402 — Average Miles Per Gallon Factors Last amended: Authority G.S. 105-262; 105-449.44; 105-449.45; Eff. January 1, 1983; Amended Eff. January 1, 1994; February 1, 1990; March 1, 1987; Recodified to 17 NCAC 12A .0401 effective November 1, 2002. Source: official text