As difficult as it might be to believe, the:
Average U.S. vehicle mileage has declined since 1988, primarily reflecting an increased proportion of SUV's,
Average U.S. vehicle mileage is now roughly the same as for the mix of automobile, light and heavy Model T trucks produced 80 years ago, and
Average 2006 U.S. vehicle mileage is considerably less than the mix of automobiles and light Model A trucks that were manufactured in 1930.
Additionally, we have far more automobiles in the world than we did in 1930, and these vehicles are traveling many more miles that was common in 1930, resulting if far greater gasoline consumption and emission of greenhouse gases.
None-the-less, it appears that there is something fundamentally amiss with a society that manufactures, and purchases, vehicles that achieve a significantly lower mileage than the vehicles that were driven by our great-grandparents.
http://arewetoast.com/automobiles-past.html