Today's engines are barely above idle speed at highway cruise. No wonder they're quiet! I actually went to smaller wheels on my daily driver (04 Ram 1500) because the engine RPM was too low. By the time the little V8 and the OD transmission worked its way through all the gears, got into overdrive, and locked up the torque converter, the thing was running 75 MPH at 2000 RPM. Any attempt to run slower resulted in constant toggling in and out of converter lockup, and/or shifting out of overdrive at the slightest hint of a hill. Cruise control? "Fuggedaboutit!" To keep the transmission from eating itself, I changed from 17" wheels to 16". Now I can run 65 or a little less at 2K, which is the place the engine likes to cruise.

If you're not running a stovebolt engine 3K RPM at highway cruise, you're lugging it.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!