Quantifying efficiency technology improvements in U.S. cars from 1975–2009

Quantitative measurements of historic improvements in fuel efficiency technology help to illuminate the feasibility of future fuel economy standards. Past investigations have produced widely varying estimates of this rate of improvement, though all seem to indicate that fuel consumption reductions implied by the 2025 U.S. CAFE standards cannot be met solely through technological improvements at historic rates. In this paper, we use the...