The President’s proposal would also order more gains in fuel efficiency for cars and lighter trucks.

President Obama today ordered the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Transportation (DOT) to institute the first regulation to increase fuel efficiency and decrease greenhouse gas pollution from medium- and heavy-duty trucks for model years 2014-2018.

He also called for national regulations on increasing fuel economy beyond the current ones, which stipulate that new light vehicles  must average at least 35.5 miles to a gallon of fuel by  2016 for combined city and highway driving.

The President’s proposal would order further, unspecified improvements in fuel efficiency for cars and light trucks made in 2017 and beyond. California still has the ability to impose its own regulations after that, and automakers are desperate to have a long-term national policy imposed. How this unfolds in Congress is uncertain, but the Administration called for action before the end of this year. ( See Administration Rolls Out New Fuel Economy Rules )

The Obama announcement comes as the BP oil spill in the Gulf of Mexico continues to release the equivalent amount of oil spilled by the Exxon Valdez every day or two. No end to what is called the largest environmental disaster in U.S. history  is in sight.

It is estimated that trucks currently use more than two million barrels of oil every day, and average 6.1 miles per gallon. Trucks also emit 20% of the greenhouse gases related to transportation.

The President said in a White House Rose Garden photo opportunity that preliminary estimates indicate the potential for significant fuel efficiency gains of as much as 25% and greenhouse gas emissions reductions for large tractor-trailers, which represent half of all GHG emissions from the sector.

“This will bring down costs for transporting goods, serving businesses and consumers alike. It will reduce pollution,” Obama said.

“And, just like the rule concerning cars, this standard will spur growth in the clean energy sector. We know how important that is. We know that our dependence on foreign oil endangers our security and our economy. We know that climate change poses a threat to our way of life – in fact, we are already beginning to see its profound and costly impact. And we know that our economic future depends on our leadership in the industries of the future,” Obama said.

President Obama also directed the Department of Energy to provide increased support for deployment of advanced vehicles, including electric vehicles, and ordered EPA to reduce non-greenhouse-gas pollutants from motor vehicles.

Today’s announcement follows  a new national fuel economy policy announced by  President Obama one year ago, which increased fuel economy and thereby reduced greenhouse gas emissions for new cars and light-duty trucks manufactured and sold in the U.S. during model years 2012-2016.

As a result, last month the EPA and DOT issued final regulations, which established for the first time a harmonized “National Program.” The Administration claims that this will save 1.8 billion barrels of oil and reduce greenhouse gas emissions by nearly one billion metric tons – equivalent to taking 50 million cars off the road – over the lifetime of vehicles sold in model years 2012-2016.

According to a Union of Concerned Scientist analysis, raising the average fleetwide fuel economy of new vehicles to 55 miles per gallon (mpg) by 2030 would reduce oil consumption by 3.9 million barrels per day in that year, save consumers $158 billion — even after accounting for the cost of new technology — and cut heat-trapping emissions by 661 million metric tons of carbon-dioxide-equivalent.

The U.S. currently imports 11 million barrels of oil each day.