In August 2017, Pruitt began reconsidering new car emissions standards. Pruitt has been planning to reduce federally mandated corporate average fuel economy. Pruitt has proposed to repeal heightened emissions standards on "glider trucks", which are semi-trailer trucks that have new bodies but old engines. Pruitt had requested public comment on reductions to the Renewable Fuel Standard after being encouraged to do so by Carl Icahn. Pruitt has since traveled to Iowa twice to promote the repeal of the Clean Water Rule and to promise support of corn ethanol production.