The Senate approved a compromise proposal on fuel efficiency standards via an unexpected voice vote on June 21. The bill would enact higher standards for the first time in thirty years.

The measure calls for vehicles to uniformly achieve 35 miles per gallon by 2020, up from the current level of 25 mpg.

Reactions to the bill were mixed. The major automakers had no initial comment. Industry lobbyists had backed a separate plan that would have softened the increases to just 36 mpg for passenger vehicles by 2022 and thirty for light trucks in 2025.

The auto companies have routinely asserted that stringent increases in fuel efficiency standards would cripple an already deeply troubled industry, a position environmentalists and many lawmakers dismiss.

Sen. Byron Dorgan, a Democrat from North Dakota commenting on the measure said, "It will not do damage to the industry. It will not take away your pickup truck."

The Consumer Group Public Citizen, however, described the measure as a "step backward" while the Consumer Federation of America voiced its support saying the new standards will significantly decrease oil imports and cut emissions.

Sen. Thomas Carper, a Democrat from Delaware who co-sponsored the initiative said, "If we're really smart, we'll find a way to make this new approach to fuel efficiency work -- to make it work for domestic auto companies, their shareholders, their employees and our nation to reduce our dependence on foreign oil."

The measures, part of a larger energy bill, cleared the Senate chamber late Thursday night.