An ethanol-gasoline blend sold at New Mexico gas stations reduces an engine's power, leading to poorer vehicle mileage, AAA said.

In addition, the state environmental department said E-10 -- a 10 percent ethanol, 90 percent gasoline mix -- while reducing emissions of some hazardous pollutants, increases emissions of others, the Albuquerque Journal reported Friday.

"Recent studies have shown increased ethanol in gas will increase ozone concentrations," said Marissa Stone, New Mexico Environment Department spokeswoman. But since no "ozone non-attainment areas" are in New Mexico, ethanol blends can be sold all year, she added.

The Energy Information Administration projects additional ethanol usage in 2008 will reduce average fuel economy by 0.5 percent.

Refinery officials told the Journal a federal mandate set a higher renewable-fuels standard for 2008, together with an incentive for fuel blenders selling E-10, the federal designation for gasoline with a 10 percent ethanol content.

"I think you're going to see 99 percent of the stations in Albuquerque moving to it in the next several months," said Larry Ross, Shell Oil's area manager for New Mexico, Colorado and West Texas.