Fuel Efficiency Has Increased By 71% Since 1973
Thanks to a suggestion in a comment on a previous post by Mad Toothfish, the chart above shows the significant increase in fuel efficiency over time, based on "miles per gallon (m.p.g.)" data from the EIA (Figure 23) for passenger cars. Compared to 1973, when the average passenger car got only 13.4 m.p.g., fuel efficiency increased to 22.9 m.p.g. by 2005, a 71% increase in efficiency in a 32-year period!