WASHINGTON - The Senate voted to require average fuel economy of 35 miles per gallon for new cars, pickup trucks and SUVs by 2020, raising efficiency standards that have not changed significantly for nearly two decades.

The fuel economy measure was added to a broad energy bill without a roll call vote even as senators were holding a news conference announcing the compromise.

The legislation for the first time would establish a single fuel economy standard applicable to not only cars, but also SUVs and pickups which currently have to meet less stringent requirement.

Automakers are currently required to meet an average of 27.5 mpg for cars and 22.2 mpg for SUVs and small trucks. The car standard has not changed since 1989, though the truck requirements have been increased slightly by the Bush administration.

The measure tacked onto the energy bill would require a 35 mpg fleet average — including SUVs and pickup trucks — by 2020, and require that automakers make half of their vehicles capable of running on 85 percent ethanol fuel by 2015.

The compromise removed a requirement that automakers would have had to meet an additional 4 percent increase per year for 10 years after 2020. The ethanol flex-fuel requirement also would have been three years longer.

Automakers had strongly opposed the 4 percent requirement, saying it was not achievable and would have required them to make vehicles with a fleet-wide average of 52 mpg by 2030.

Auto industry leaders came to Capitol Hill several weeks ago saying they could not meet the kind of fuel use increases being contemplated. Industry executives and car dealers visited Senate offices this week in last minute lobbying and urged senators to approve a less stringent measure