Summary

Pursuant to a congressional request, GAO provided information on states' gasoline octane testing programs and the extent of octane mislabelling.

GAO found that: (1) 20 state and territory officials reported that they had octane testing programs, and 31 reported that they did not; (2) 7 of the 31 officials without programs indicated that they tested in response to complaints, and 13 officials planned to recommend testing programs within 3 years; (3) states with programs differed in the extent of testing and the manner in which they compiled test data and defined violations; (4) most states providing test data showed octane violations in less than 1 percent of the tests; (5) 11 officials indicated that octane mislabelling was a problem in their states, 18 reported that mislabelling was not a problem, and 21 reported that they had no basis to determine whether there was a problem; and (6) 16 state officials reported that they obtained octane rating certifications from refiners and distributors, and 31 said they did not.