An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Fuels Registration, Reporting, and Compliance Help

Does EPA have curves showing the effects of different oxygenate levels on the resulting T50/T90?

The Agency has developed no such curves. However, since the Complex Model requires the use of E200 and E300 instead of T50 and T90, the effects of different oxygenate levels on E200 and E300 can be back-calculated from the resulting dilution of the base gasoline.(7/1/94)

This question and answer was posted at Consolidated List of Reformulated Gasoline and Anti-Dumping Questions and Answers: July 1, 1994 through November 10, 1997 (PDF)(333 pp, 18.17 MB, EPA420-R-03-009, July 2003, About PDF)