Y'know, I've searched online to find exactly that information on my engine, or any similar engine. I've had no luck finding it, so far. I know I've got the brochure for my car in my house somewhere. I'm going to pull it out and see if I can get a hardcopy of the power-torque curves. IF so, I should be able to post specific information on what the curves look like for my particular engine. I didn't mean to focus on my engine in particular. I just thought it was REALLY INTERESTING to learn that Otto Cycle engines achieve maximum fuel efficiency near 40% of redline. (especially as that agrees EXACTLY with the performance I have observed over many years of driving vehicles with Otto Cycle engines) Knowing THAT particular data point makes it a little easier to pick a new car when you are car shopping. But only if the car has a tachometer. If it doesn't have a tachometer, then you have no idea what ground speed the engine was made to be most efficient at. That is, without running many hundreds of miles of tests first. :)
Best I can come up with at the moment is that the engine in my current car is a Mitsubishi "4g64" 2.4L inline 4. -Dave
