...The Obama administration claims the new measures will save 1.8 billion barrels of oil over seven years. But that claim assumes new-car buying habits continue unabated and that people will want to buy expensive, tiny cars. If people instead elect to purchase bigger, cheaper used vehicles, there will be no reduction in consumption; those used vehicles are the same "guzzlers" we're driving today. The fuel economy gains we might have seen with reasonable mileage targets for new vehicles won't be realized if fewer new vehicles are sold. Worse, the auto industry will continue to shrink because of the decrease in new-vehicle sales.