Mileage Miscalculation

Automobile regulation that improves fuel efficiency raises the price of new cars. That in turn raises the price of used cars, as some buyers avoid higher new car costs by buying used ones. This unsurprisingly reduces the number of used cars that get scrapped. And since used cars have worse gas mileage than new ones, this unintended longer used car lifespan negates about 18% of expected gasoline savings.