So, I was watching some Donald Duck cartoons from my Christmas gift: The Chronological Donald Vol. 4, 1951-1961, and there was a bit where Donald won a car that got 25 miles to the gallon (in 1951). Not knowing if it was an exaggeration, I did some research, and found that some cars of that era got that mileage!
Check out the above Blog for scans of old ads of the time.
I've found one graph that showed gas milage from the early 1970's to the present, but I'd really love a graph that showed milage since the inception of the automobile! It would be great if it had the highest & lowest milage for each class for new models of each year.
I'm also interested in if any additions to cars have helped or hurt overall mileage (catalytic converters, types of engines, etc)
If there was a big gain or dip in any given year, I'd like to know the root cause.
So, if you have heard of any such graph, please let me know where I can find it!