As part of President Obama's commitment to clean energy, the U.S. Department of Transportation and the Environmental Protection Agency have established new national standards for fuel economy and greenhouse gas emissions
, requiring automakers to improve fleet-wide fuel economy and cut greenhouse gas emissions by about 5 percent every year. The new rules start with 2012 model-year cars and light-duty trucks.

In addition, the National Highway Traffic Safety Administration has established fuel economy standards that strengthen each year, reaching an estimated 34.1 mpg for the combined industry-wide fleet for model year 2016.

"These are the first national standards ever to address climate change," said Gina McCarthy, EPA assistant administrator for air and radiation. "Over the coming years, America will witness an amazing leap forward in vehicle technologies, delivering fuel efficiency that will save us money and protect the environment."

NHTSA and EPA hope the standards will lead to more widespread adoption of conventional technologies that are already in commercial use, such as more efficient engines, transmissions, tires, aerodynamics, and materials, as well as improvements in air conditioning systems. Although the standards can be met with conventional technologies, EPA and NHTSA also expect that some manufacturers may choose to pursue more advanced fuel-saving technologies like hybrid vehicles, clean diesel engines, plug-in hybrid electric vehicles, and electric vehicles.

According to the EPA, the rules could potentially save the average buyer of a 2016 model-year car $3,000 over the life of the vehicle and, nationally, will conserve about 1.8 billion barrels of oil and reduce nearly a billion tons of greenhouse gas emissions over the lives of the vehicles covered.

"These historic new standards set ambitious, but achievable, fuel economy requirements for the automotive industry that will also encourage new and emerging technologies," said Transportation Secretary Ray LaHood. "We will be helping American motorists save money at the pump, while putting less pollution in the air."

Public comments related to the September 2009 proposed rules were supportive, EPA says.

Because credits for air-conditioning improvements can be used to meet the EPA standards but not the NHTSA standards, the EPA standards require that by the 2016 model-year, manufacturers must achieve a combined average vehicle emission level of 250 grams of carbon dioxide per mile. The EPA standard would be equivalent to 35.5 miles per gallon if all reductions came from fuel economy improvements.

The Alliance of Automobile Manufacturers, made up of 11 car and light truck manufacturers, announced its support of the new rules.

"America needs a roadmap to reduced dependence on foreign oil and greenhouse gases, and only the federal government can play this role," said Dave McCurdy, president and CEO, Alliance. "Today, the federal government has laid out a course of action through 2016, and now we need to work on 2017 and beyond."

For more information on potential medium- and heavy-duty vehicle fuel consumption standards, see Washington Editor Oliver B. Patton's recent story.