U. Mich - US Vehicle Fleet Fuel Efficiency 3 MPG Higher Than In 1923 - New Scientist

The average fuel efficiency of the US vehicle fleet has risen by just 3 miles per gallon since the days of the Ford Model T, and has barely shifted at all since 1991.

Those are the conclusions reached by Michael Sivak and Omer Tsimhoni at the University of Michigan Transportation Research Institute in Ann Arbor. They analysed the fuel efficiency of the entire US vehicle fleet of cars, motorcycles, trucks and buses from 1923 to 2006.

They found that from 1923 to 1935 fuel efficiency hovered around 14 mpg (5.95 km/l), but then fell gradually to a nadir of only 11.9 mpg (5.08 km/l) in 1973. By 1991, however, the efficiency of the total fleet had risen by 42 per cent on 1973 levels to 16.9 mpg (7.18 km/l), a compound annual rate of 2 per cent.

The improvements made up to 1991 were in response to two international events – the 1973 oil embargo by the Organisation of Petroleum Exporting Countries (OPEC), and the Iranian Revolution of 1979.

EDIT

http://www.newscientist.com/article/dn17506-us-vehicle-efficiency-hardly-changed-since-model-t.html

It makes no mention of the changes in cars, trucks, buses, and motorcycles since 1923 in the areas of safety, comfort, reliability, maintenance, or utility.

I am sure the average fuel economy of large, over the road trucks is substantially less than it was in 1923, but a comparison of transporting 50,000 pounds for freight from Jacksonville, Florida to Los Angles, California in 1923 and today would be interesting.

It is one thing to focus on an important issue like fuel economy, but to bias the story to the point of insulting the readers is another thing all together.

More on who owned cars in the 1920s, from about 1909 till the Great Depression the two biggest markets for cars where "middle class American" (Which EXCLUDED most people who lived in cities, Middle class in that time period meant what we referred to as the "Upper Middle Class" people making at least twice the Median income. Median Income today is about $42,000, so we are talking about people whose house hold income exceeds $84,000 in todays dollars) AND rural farmers.
http://books.google.com/books?id=LQDoAAAAIAAJ&pg=PA13&lpg=PA13&dq=Car+population+in+1923&source=bl&ots=X9RazhV1To&sig=oq_ITuXG3MAVy1Jj01JFN7LtypI&hl=en&ei=8eppSoHDD4mKMavXlNsP&sa=X&oi=book_result&ct=result&resnum=8

In my home town of Pittsburgh, Streetcar ridership peaked in 1927, but the subsequent decline was minor (Do more to the economic downtown of the Great Depression then a conversion to Automobiles) till after WWII (When deep declines hit ALL street cars system forcing the remaining rural lines to close down in the early 1950s and urban lines becoming unprofitable do to steep decline in usage).

An example of a Rural Streetcar line that ended service in 1952, the West Penn Electric Railway:
http://en.wikipedia.org/wiki/West_Penn_Railways

The Automobile industry is generally NOT considered a "mature" industry till 1954, when more people purchased cars to replaced cars their already owned as opposed to people who were buying cars for the first time (My Father's family did NOT own a car till 1947 for example).

My point is comparing 1923 with today is like comparing ancient Rome with today's city, you not only have to look at just one aspect of the historical situation (In the above case the Automobile) but also how it related to the rest of society.

Lets remember that in 1923 the Automobile was becoming more and more important (Like electronics today) but most people still used older technology to get around (Streetcars, bicycles, horses and even long distance foot traffic). Even today, with electronics more and more important, electronics by itself does NOT get us to the store to buy food to eat (Or get the food to the store, through electronics has improved HOW the food gets to the store and to home).

We also have to look at WHO was buying a car in 1923, Farmers and Upper Middle Class Americans (The rich also were buying but even then to small a market to cater to if you really wanted to make money). Both groups wanted LARGE CARS, the farmers to haul people and products to the field and to market, Upper Middle Class Americans to show people they had made it (Which was also a factor among farmers, but less then Middle Class Americans thus urban people stayed with streetcars and buses till after WWII, inner city people were the last people to embrace the automobile in mass numbers and in some places even in the US, New York City for example, such inner city people still have NOT embraced the car culture, through most own a car).