EPA sulfur in gasoline test results

Sulfur content in gasoline is regulated by the EPA, for both conventional and reformulated gasoline (RFG).

The two most recent revisions to sulfur content standards in gasoline are the introduction of Tier 3 standards, effective from January 1, 2017, and the transition into Tier 2 standards, finalized on January 1, 2006. Both of these standards have allowed trading of sulfur credits accumulated in prior years: therefore, years in which the weighted-average sulfur content level of gasoline indicated in the EPA’s testing data exceeds the regulated limit may not necessarily indicate actual non-conformity with regulations. Conformity is partly a function of the use of these banked sulfur credits; it is not possible, from the EPA’s public disclosures at least,