(NAFB.com) –  Lawmakers are advancing legislation that would allow year-round nationwide sales of E15 gasoline, a move backed by corn growers and ethanol producers who say it would expand fuel demand and lower prices. E15 contains 15% ethanol, compared with the standard E10 blend sold in most markets. Summer sales have faced restrictions in some areas because of federal air-quality rules, though temporary waivers have been granted in recent years. Supporters say permanent access would create a more predictable market for biofuels and increase corn demand at a time when farm income has softened. Retailers and renewable fuel groups also say consumers would benefit from another lower-cost fuel option. Some refining interests have sought regulatory adjustments as part of any compromise. Analysts say the debate reflects the continued political importance of ethanol policy in farm states and the broader Midwest fuel market.