The EPA's taken another step towards wide distribution of gasoline mixed with 15% ethanol by letting manufacturers to register as suppliers. E15 still has to clear federal tests and become a registered fuel in individual states. The folks who make Ethanol then have to talk petroleum marketers to sell it at gas stations. Most of the Ethanol sold is 10% ethanol, 90% gas. The new blend would only be used in vehicles made after 2001.