WASHINGTON - The U.S. Environmental Protection Agency said it is delaying a decision on whether to approve a waiver request that would allow E15 (a 15-percent ethanol fuel blend) to become available to all vehicles, Dow Jones Newswires reported. 

The EPA said more testing needs to be performed to assess the impact on vehicles, but the agency expects to have a decision in the fall. 

The EPA told Dow Jones Newswires that it has not yet decided whether only newer car models or older ones as well would be approved to use E15, if in fact the waiver is eventually granted. 

The ethanol industry has pushed aggressively for the agency to lift the 10-percent ethanol blend cap to 15 percent. But automakers, expressing concerns that such a move could threaten the performance and durability of some vehicles, have called for further research. 

The waiver request was submitted more than a year ago by Growth Energy, an ethanol industry association and lobbying group.