Vehicle fuel efficiency standards increased in 2011 after almost 30 years without changes. Corporate average fuel efficiency (CAFE) standards for cars and light trucks were instituted in 1975 in response to the 1973 Arab oil embargo. As a result of the standards, car efficiency rose from 12.9 to 27.5 miles per gallon (mpg) in ten years.
At about the same time, sales of SUVs, which are classified as light trucks with 1975 fuel efficiency requirements of 20.7 mpg, rose to 50 percent of vehicle sales.
The 2007 Energy Independence and Security Act mandated an average fuel efficiency of 35 mpg for passenger cars in 2020 while allowing for differing fuel economy standards based on the size of the vehicle.
Current, revised standards will require a combined fleet-wide fuel economy of about 41 mpg in 2021 and about 49 mpg in 2025.The allowances for different vehicle types means that in 2025 a Ford Fusion would be required to get about 55 mpg and a Chevy Silverado would need to get 33 mpg.
The latest standards were released in 2011 and include requirements for reductions in greenhouse gas emissions.
Costs and Benefits
The National Highway Transportation Safety Administration (NHTSA) estimates that fuel savings will far outweigh the vehicle costs of these standards.
Opponents express concern that more fuel-efficient vehicles will be less safe, and NHTSA studies confirm that vehicle weight reduction, which is necessary for improved fuel efficiency, results in more vehicle crash deaths. However, past studies also suggest that car safety has more to do with engineering design than vehicle size.