No. But if 3200RPM was the most fuel-efficient engine speed, your average fuel economy would be reduced by running the engine at a significantly different RPM. In other words, 80MPH up a 6% grade might get 25MPG at 3200RPM. Meanwhile, 80MPH up a 6% grade might get 20MPG at 4000RPM. Load can affect the overall average fuel economy, but it's not going to change the fact that you'll still get better fuel economy if you run your engine at the speed at which it is wasting the least amount of energy in the form of heat. The otto cycle engine is terribly inefficient in the sense that most energy obtained from burning gasoline is converted to heat. But there is a certain RPM that each engine is most fuel efficient at, because near that RPM, it is converting a greater percentage of potential energy (from burning air-gas mixture) into kinetic energy. (you know, what keeps the car moving)
I don't know why I even bother to try to explain this. Anyone could do the research and find this out for themselves. It's not a theory, and it's certainly not MY theory. But when I post it, I'm branded a liar, or told that I simply misunderstood what I read. Yeah, whatever. Before responding, answer these questions, and please LOOK UP the answers . . . don't just make something up . . .
1) What percentage of potential energy is wasted as heat energy by the otto cycle engine? 2) At what RPM does the otto cycle engine produce the most kinetic energy in relation to the amount of fuel consumed, and waste the LEAST amount of energy as heat, in relation to the amount of fuel consumed?
I'll give you a hint on number two . . . there is no magic number that applies to every single engine. Otherwise, it would be smartest to remove the accelerator pedal from all vehicles with otto cycle engines. And the tranny, for that matter. But there is a way to calculate this RPM. There are a couple of ways, actually. Oh, and *they aren't my ways*. So before you scream at the top of your lungs that I'm wrong, keep in mind that I'm not making this poo up. Do the research yourself. Or choose to remain ignorant. -Dave
