Staff on Your Behalf
Robert Shull Answers Your Question

Bob Shull takes your fuel economy standards questions.

Robert Shull is the deputy director of the Auto Safety and Regulatory Policy division of Public Citizen.Robert Shull is an expert in issues dealing with regulatory policy, risk assessment, cost-benefit analysis, fuel economy and auto safety

Question: Will increasing fuel economy standards make cars smaller and less safe?

The auto industry has promoted the myth that increased fuel economy means that vehicles will necessarily become smaller and lighter, and that as a result of reducing size and weight, they will be less safe. While the physical principles of collision suggest that the heavier object “wins” in a collision, car crashes are not a matter of “simple physics.” Vehicles are designed to absorb impact forces, and the front and side of vehicles are designed to “crumple” to lessen the forces of impact before they reach the occupants.

Fuel economy improvements can be achieved in a variety of ways, not just reducing size and weight. Contrary to popular conception, the fuel economy improvements of the late 1970s and early 1980s were not primarily a result of reducing size and weight – 85 percent of fuel economy improvement came from the introduction of fuel saving technologies.

The bigger safety concern is incompatibility – that is, the difference in size between vehicles – which has gotten much worse over the past decade, as SUVs and light trucks have gotten bigger and heavier with respect to cars. In 1979, the difference in weight between a typical car and light truck was less than 20 pounds, today it is over 1,100.

Increased fuel economy standards could encourage manufacturers to look into using lightweight materials to reduce the weight of larger vehicles, while maintaining size, which would improve compatibility and fuel economy.


December 18, 2018

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