As I was driving along today, letting my mind mull over stuff, I began to think about combustible engines. My experience as a full time traveler clearly indicates that combustible engines operate most efficiently at the lowest revolutions per minute necessary for any given speed. In my case, I can cruise on level roads at between 55 and 60 mph at only about 1500 rpm. Under those conditions I can get 22 miles per gallon while towing the trailer and 32 miles per gallon without the trailer. If I increase my speed so that the rpm number goes up to the 2,000 to 3,0000 range, I get around 14mpg with the trailer and around 23 mpg without it. This means that for my Honda, increasing my speed above the most efficient level for my engine (55 – 60 mph) to the 65 – 75 range costs at least 25% in fuel efficiency which, of course, also adds more pollutants to the atmosphere over the same distance traveled. It seems reasonable to assume that other folks in other cars would experience somewhat similar results based upon the idiosyncrasies of their engines.
Now if we multiply this result by all the vehicles (commercial ones included) driven on the highways around the USA, it would seem that we could save a lot of fuel and significantly reduce pollutants added to the atmosphere by imposing a national speed limit of say 60 mph! I know there would be a great outcry over such a move but, the energy problem and global warming have created an urgent need for universal cooperation by everyone, not unlike those that take place under wartime conditions. The speed limit would require real, full time enforcement but there are a number of ways this could be done efficiently. The use of your CRUISE CONTROL would become the norm as soon as you got out of town and on the highway to somewhere else.
This action would provide a very significant, ONE TIME, jump in efficiency immediately effective as soon as implemented! The longer term actions of improving the efficiency of combustible engines and/or finding alternative ways of providing necessary power would continue.