During a visit to Detroit last year, President Trump announced his administration would assess and correct the current vehicle fuel-economy standards, or Corporate Average Fuel Economy (CAFE). On Aug. 2, the Transportation Department and Environmental Protection Agency took action by announcing a joint proposal to update the national automobile fuel-economy and greenhouse-gas standards.

The CAFE standards are one of the reasons automakers have been lightweighting their vehicles by using aluminum and other exotic materials, with the goal of hitting the mandated fleet average of 54.5 miles per gallon by 2025.

The joint proposal lays out eight options for new national fuel-economy standards for model years 2021-26.  The goal, according to the Administration, is to create one national standard that is technologically feasible and economically practicable, while promoting energy conservation, furthering other environmental goals and preserving consumer choice. The administration’s proposed option would lock in the 2020 standards until 2026, because its analysis suggests that those standards strike the appropriate regulatory balance between vehicle improvements, environmental benefits and safety.

According to the Trump Administration, the standards implemented by the previous administration raised the cost and decreased the supply of newer, safer vehicles.