He was not even a teenager when it occurred but saw the results all through the 1930s. When the Model T was the dominate car, it had a Small radiator. Do to these small radiators the Model T could NOT climb even a Pennsylvania Mountain without having to stop halfway up the mountain and having its radiator refilled. Thus on most of the long grades on US 30 and US 40 in the Mountains of Maryland and Pennsylvania half way up the hill you had businesses that catered to these Model T Drivers (By providing them water and other refreshments as the engine cooled down).
When I traveled with my father you could still see these old (by than Abandoned) businesses. With the Model A's larger engine, the Model A could go up and down those same mountains WITHOUT overheating.
If you look at modern cars, they ALL have engines that can take on a Western Mountain in addition to our lower Eastern Mountains. Even your Civic can do so. The advantage of the Model T was its engine was turned to the roads of its day (1900-1920) which did not permit high speeds. If you kept the speed low (But high enough to stay in the Model T's highest gear) you could get great full economy. My father in the 1970s when gas was last going through the roof, remembered driving his 1949 Ford with overdrive. In that car he obtained 30mpg on the highway in the 1950s. This was just before the Interstate highway system was started so speeds on most roads was restricted by the design of the road not the car. As the Roads improved, the speeds cars could go improved, so people wanted faster cars. The Interstate Highways system really increased the demand for speed (Look at the climb of the Muscle cars in the 1960s, as the first, and easiest, part of the Interstate Highway system was finished).
In 1999 the owner of the Tenth Millionth Model T retraced the route it was driven in 1924. His biggest complaint was driving Interstate highway type roads. Roads the Model T was NOT design to be driven on. In many ways he was a road hazards on such roads (But once he was off the Interstate type highways his speed was competitive, slow but competitive).
My point here is we drive cars that reflect what we have to drive on. When the Model T was the car to buy, most roads were dirt (US 30 was only completed paved nationwide in 1926, and its cross state rival, US 22, was only paved in Pennsylvania in 1929). Today most people have NEVER driven on a dirt road and theirs cars were NOT design for driving on dirt (and this is true for many of the SUVs out there, some I would hesitate to take on a dirt road). Cars today reflect the roads condition we face today, paved over crowded highways (thus why we have A/C and Radios in the car). If we would accept a true limit of 50mph we would all drive cars with much smaller engines, smaller engines means smaller transmissions and frame to hold the engine and transmission. You could do this by restricting the size of the engine to 2 liters or smaller. Traffic will slow down do to the smaller cars with smaller engines, but not by much given todays gridlock. The worse part I read a proposal to limit car engines to 2 liters in the 1970s in Popular Mechanics (Which has always like its big cars) and that by their gun guru of the time period. This is also how Volkswagen did its 235mpg experimental car a few years ago. Very small engine small car, no acceleration but great fuel economy.
That will be the answer more than the exotic being pushed right now, very small engine (1-2 liters) powering very small cars for people to go and from work in at speeds not exceeding 30-35mph. Sounds like the Model T? Yes, but it will get 200mpg, not the Model T's 10 % of that.
One last comment, the VW 235 mpg car weigh 588 pounds with a 8.5hp engine, 101 pounds being pulled for each hp, the Model T Weigh 1200 pounds with a 20 hp engine for 60 pounds for each hp to pull, a Honda Civic weigh 2456 with a 115 hp engine or 21.35 pounds per hp being pulled). Thus the Model T is doing better than your Civic but at many of the costs of the VW 235mpg car.
The Model T Club:
http://www.modelt.org/tcars.htmlLincoln Highway and the 10th Millionth Model T
http://www.warsawcity.net/lincolnhwy.htm1908 Model T Speciafications (It had a 20hp engine, weighed 1200 pounds):
http://www.cob.montevallo.edu/LeeBS/specs.htmHonda Civic (Horse power is 115):
http://www.hondacars.com/models/specifications.asp?ModelName=Civic+CoupeSo a Civic has almost SIX times the power of a Model T (through on another site it does list Civic TORGUE HP as 13.6).
http://www.autoprestigemotors.com/civicspecs.htmlHistory of PA US 22:
http://www.pahighways.com/USHwys/US22.htmlA history of PA US 30 (a lot of duplications for in the Pittsburgh Area these two highways have been the same since 1925, but vastly different in the rest of the state):
http://www.pahighways.com/USHwys/US30.htmlVW's 235mpg car (8.5 HP, 588 pounds):
http://www.popsci.com/popsci/auto/article/0,12543,320360,00.html