The Department of Transportation today announced new fuel economy standards requiring 2011 model-year cars to average 30.2 mpg, and light trucks to average 24.1 mpg. The combined average requirement will be 27.3 miles per gallon—a 2 mpg increase above the 2010 standard, but a mere 1 percent increase over the 27.0 mpg level already achieved last year for 2008 model year vehicles.

The car standard part of today’s new Corporate Average Fuel Efficiency (CAFE) rule—a 2011 average of 30.2 mpg—is 1.2 mpg less than the car fleet average already achieved for model year 2008 cars, according to DOT statistics.

Environmentalists and energy advocates were disappointed by the rule—and were uncertain about the motivations behind the decision. “The Administration apparently has the economic crisis in mind,” said John DeCicco, senior fellow, Environmental Defense Fund. “But it’s not clear that any extra cost would be required by automakers to achieve fuel economy levels they’ve already achieved.”

An energy bill mandating an average fuel efficiency of 35 miles per gallon for cars and trucks by 2020 was signed by President Bush in late 2007, but specific figures and dates were not determined for the phase-in period between 2011 and 2015. President Bush passed the responsibility of determining specific timelines and rules to the Obama Administration. The new administration had only two months to develop the rule, which must be issued before April 1.

The pressure to meet higher fuel efficiency standards is one of the forces behind carmakers’ move toward smaller fuel-efficient vehicles, hybrids and eventually plug-in vehicles. It’s unlikely that the relatively easy targets for 2011 will affect those plans—especially considering the more critical dialogue taking place between automakers, federal regulators, and California regulators. All parties are working toward an aggressive but realistic single nationwide fuel efficiency standard.

The new rule did omit language attacking California’s right to set automobile greenhouse gas standards previously included in former President Bush’s proposals. On Jan. 26, President Obama fulfilled a campaign pledge by issuing an executive order telling the Environmental Protection Agency to reconsider its rejection of California’s rules to regulate greenhouse-gas emissions. The California regulations—considered by most to be tougher than federal rules—could require the rough equivalent of more than 40 mpg by 2020.