President Barack Obama wants the government to start working on fuel efficiency and greenhouse gas emissions standards for cars and trucks in the model year 2017 and beyond.
An administration official says agencies, for the first time, will be asked to develop standards for heavier trucks as well.
The official spoke on condition of anonymity before a White House announcement expected Friday.
In April, the administration rolled out rules for 2012-2016 model year vehicles that were aimed at reaching a 35.5 miles-per-gallon average — nearly 10 miles per gallon more than now.
Obama also plans to push for development of more electric-powered and other next-generation cars.