The time has come to set fuel economy standards for the years 2017-2025, and it appears the Obama administration is aiming at the ambitious average of 56 MPGs across all fleets.

Automakers are required to conform to government regulations that set a certain average when it comes to fuel economy, known as the Corporate Average Fuel Economy (CAFE). The Detroit Free Press reports that the Obama administration has sat down Detroit's "Big Three" to hammer out regulations up through 2025.

The rumored total has provoked reactions from both dealers and environmentalists.

"Overly ambitious standards set 14 years in the future risk severe economic harm if consumer wants and needs are not met," Bailey Wood, a spokesman for the National Automobile Dealers Association, told the news source.

Meanwhile, green activists say that the Obama administration should aim higher, for a total close to 60 MPGs.

It's difficult to predict what fuel-saving technology will be like in 2025. Automakers have already begun to introduce electric and hybrid vehicles in an effort to meet the current standards for fuel economy. The problem is that some of the top-selling vehicles, like pickup trucks, carry MPG ratings that are well below the average requested by the government.