https://www.sciencedaily.com/releases/2020/09/200903105600.htm

Using data including household spending data, oil use, and greenhouse gas emissions, the researchers found that the standards (known as the CAFE standards), which were first enacted in 1975 as a way to reduce dependence on foreign oil after the oil crisis, set well-defined societal objectives and were cost-effective, fair, durable and adaptive. The standards required automakers to produce more efficient vehicles over time, increasing the number of miles per gallon required of their vehicle fleets. The researchers cite that the standards saved $5 trillion in fuel costs and prevented 14 billion metric tons of carbon from being released into the atmosphere, the equivalent of the United States eliminating all emissions from all sectors for nearly three years.

"It has been one of the most effective policies to date," said Judi Greenwald, a co-author of the study, former top U.S. Department of Energy official and non-resident fellow at the Princeton University's Andlinger Center for Energy and the Environment.