The new rules mean that "by the middle of the next decade, your cars and trucks will ... go twice as far on a gallon of gas," Obama said. "That will save you money. That helps our national security, and it helps our environment."
The auto industry has generally supported the fuel efficiency requirement, arguing that having a national standard is better than having differing state rules. States such as California had previously implemented their own standards for gas mileage, and others large states have tried to follow suit.
The mileage standard has also been cheered by environmentalists, who have pushed for the measures to reduce pollution from automobiles.
Under the new rules, which were finalized by the Obama administration last month, automakers will have to begin producing cars that achieve higher miles per gallon as early as 2017. The requirement will gradually increase annually until it reaches 54.5 miles per gallon in 2025.
The Obama administration has said the rules will provide an average fuel cost savings of more than $8,000 over the lifetime of a vehicle when they are fully implemented.
—This post was updated with new information at 5:48 p.m.