August 1, 2011
President Obama recently unveiled a plan to sharply increase auto fuel economy. The proposal would require the companies to reach average fuel efficiency across their U.S. fleets of 54.5 miles per gallon by 2025. The good news this would lower US oil use by 2.2 million barrels a day over the next 15 years, and accordingly cut the amount of money flowing to OPEC. It would also cut more than 6 billion tons of carbon emissions during this period of time. The bad news is according to The Center for Automotive Research, this requirement cost about $6,700 extra per car. It is also absolutely obvious that in order to achieve such fuel efficiency, the automakers would have to make the cars much lighter. Lighter cars of course are less safe. In a head-on collision, a lighter car will always have larger change in velocity due to Conservation of Momentum law (see Hyperphysics Concepts). So, no matter what anyone tells you, new fuel economy standards will hurt vehicles safety simply due to the laws of physics, even though the new cars may meet National standards for car crash safety. The trick is, during the compliance tests the car is being crashed against a still wall. Properly designed lightweight cars can perfectly pass these tests and claim five-star safety rating. However, they will have an obvious disadvantage in real conditions if collided with heavier cars. If more fuel-efficient cars offer us, the consumers, a true advantage, why mandate it? Should not their production and sales be driven by the market forces?