But thats exactly my point, you cant include everything unless you want to turn a basic how-to into an instruction manual. Cover the fundamentals of an engine and give little interesting facts like that regarding hybrids. I think your really having a hard time grasping what basic is when you mention things like 'they covered this, but not that', yes thats cause its BASIC.

Sure, but again: "how accelerator pedal tells engine to make higher vroom noise" is a very very basic part of understanding an engine.

Omitting it leads to a big hole in the reader's understanding, since the accelerator pedal is likely their only method of interacting with an engine.