CAFE's Three Strikes - It Should be Out

Brief Analyses | Energy and Natural Resources | Regulations

No. 388
Wednesday, February 13, 2002
by H. Sterling Burnett

The federal Corporate Average Fuel Economy (CAFE) standard was enacted during the 1975 energy crisis. It required auto manufacturers to meet certain mileage standards, measured in Miles Per Gallon (mpg), across a manufacturer's entire fleet of vehicles. CAFE was originally proposed as a means of reducing America's dependence on foreign oil.

  • Original CAFE standards were 18 mpg for cars and 15.8 mpg for light trucks up to 6,000 pounds.
  • Current CAFE standards are 27.5 mpg for cars and 20.7 mpg for light trucks.
  • In the future, CAFE advocates want Congress to set fuel economy standards at 40 mpg for both cars and light trucks.

Legislators, noting CAFE's inability to reduce reliance on foreign oil, among other problems, have placed a moratorium on increases in the CAFE standard. But in the aftermath of the September 11th terrorist attacks, CAFE supporters are mounting a two-pronged justification for raising CAFE standards. They are again raising the specter of energy "security," and also are arguing that increasing the mpg standard for cars and light trucks will help reduce global warming.

CAFE has three strikes against it:

  • The best evidence suggests that raising CAFE standards will not reduce U.S. dependence on foreign oil.
  • Even if human activity is contributing to global warming, raising CAFE standards will have little or no effect.
  • CAFE standards - both at their present level and at the proposed higher levels - pose a significant risk to life and health.

Strike One: CAFE Has Not Reduced Foreign Oil Consumption.

To reduce America's reliance on foreign oil, CAFE forced auto manufacturers to meet certain mileage standards or pay a fuel consumption tax for vehicles not in compliance. Since 1974, domestic new car fuel economy has increased 114 percent, and light truck fuel economy has increased 56 percent. Yet over this same period, imported oil has risen from 35 percent of the oil consumed in the U. S. in 1974 to more than 52 percent today.

This improved fuel economy, coupled with declines in oil and gasoline prices, made automobiles significantly less expensive to drive. And when driving becomes cheaper, almost everyone does more of it.

Today, on the average, people drive twice as many miles as they did when CAFE was enacted. There is no evidence that a mandatory increase in U.S. fuel economy standards will reduce future U.S. dependence on foreign oil.

Strike Two: CAFE Would Not Reduce Global Warming.

The question of whether human activity causes global warming is still very much in dispute. Many scientists and environmental advocates believe that the last century's substantial rise in greenhouse gases is causing a dangerous increase in global temperature.

In particular, they point to rising CO2 emissions as the main culprit contributing to global warming. They argue that increasing U.S. fuel economy standards would reduce fossil fuel use and decrease the amount of CO2 released into the atmosphere by cars and light trucks.

The best evidence again indicates that this argument is flawed. As pointed out, higher fuel economy standards make driving less expensive. People do more of it, resulting in little or no decrease in overall fuel consumption.

Casting further doubt, the U.S. Environmental Protection Agency (EPA) and the National Academy of Sciences (NAS) have both issued reports questioning whether raising CAFE standards will decrease global warming.

The EPA estimates that car and light truck emissions in the U.S. make up, at most, 1.5 percent of all human-caused greenhouse gas emissions. As a result, even if human activities do cause an increase in global temperature, raising CAFE standards to 40 mpg would reduce the car and light truck portion of greenhouse gases by less than one-half of 1 percent - a negligible amount.

The NAS study found that higher CAFE standards could actually be counter productive in fighting global warming, stating:

". . . [R]eplacing the cast iron and steel components of vehicles with lighter weight materials (e.g., aluminum, plastics or composites) may reduce fuel consumption but would generate a different set of environmental impacts, as well as resulting in different kinds of indirect energy consumption."

"Greenhouse gas emissions from the production of substitute materials, such as aluminum or carbon fibers or plastics, could substantially offset decreases of those emissions achieved through improved fuel economy."

In other words, while increasing CAFE standards might reduce greenhouse gas emissions from automobile tailpipes, these reductions would be offset by increases in emissions from the new technologies needed to produce more efficient cars.

Strike Three: CAFE Kills.

To improve fuel economy, auto makers primarily reduce the size and power of vehicles. Unfortunately, this downsizing has tragic consequences (See Figure) . As far back as 1989, consumer advocate Ralph Nader admitted that "larger cars are safer - there is more bulk to protect the occupant." Numerous studies have proved this point. For example:

  • Researchers at Harvard University and the Brookings Institution found that, on average, for every 100 pounds shaved off new cars to meet CAFE standards, between 440 and 780 additional people were killed in auto accidents - or a total of 2,200 to 3,900 lives lost per model year. [See the figure.]
  • National Highway Traffic Safety Administration (NHTSA) data indicate that 322 additional deaths per year occur as a direct result of reducing just 100 pounds from already downsized small cars, with half of the deaths attributed to small car collisions with light trucks/sport utility vehicles.
  • Using data from the NHTSA and the Insurance Institute for Traffic Safety, USA Today calculated that size and weight reductions of passenger vehicles undertaken to meet current CAFE standards had resulted in more than 46,000 deaths.

Since the laws of physics will not change, requiring all vehicles to be smaller increases everyone's overall risk of death or injury in auto accidents. Insurance data bear this out; occupants of small cars do worse than passengers of larger sedans, minivans or sport utility vehicles (SUVs) in every kind of accident.


Raising CAFE standards will neither decrease U.S. reliance on foreign oil nor reduce the chances of global warming, but it will result in more driver and passenger fatalities. Since the current proposal to increase CAFE standards would set the same standard for cars, light trucks, SUVs and minivans, everybody would be equally unsafe. Worse, since the overwhelming majority of minivan and SUV owners are families, many of these additional casualties would be children.

CAFE is morally bankrupt and an indefensible public policy - an experiment that has killed almost as many people as the number of military personnel lost in the Vietnam war. In baseball, when a batter has three strikes, he's out. CAFE should likewise be retired.

H. Sterling Burnett, Ph.D., is a Senior Fellow with the National Center for Policy Analysis.

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