Alexander Rogge
But those old mantras are based on evidence. That's why they set the limit to 55, not 75 during the 1970s oil embargo. Modern cars are relatively more efficient but they can't perform reverse-physics magic. Notice how vague you are? You don't know what you're talking about.
We won't look at WHAT graph? Let's see your supposed graph, and it better not be from www.motorists.com. Don't quote your own Bible.
The link below has a simple but accurate graph, and there are many others with the same bell-curve of speed vs. MPG. Notice how the curve falls off rapidly after 50-60 MPH. You'd have to deliberately build a car with quirky gearing to defy that graph.
Higher RPM (in top gear) means more fuel pbutting through the cylinders to match the higher air volume. That's how engines work.
All power comes at a price, even if the engine may feel "smoother" at a higher speed. Stick your hand or head out the window to really feel the drag the engine is fighting. More drag means more power needed, which means more fuel burned. Once you're in top gear, higher RPMs can't possibly boost efficiency except in freak circumstances.
C.T.
