Ha! I wish I could cruise at 3,000rpm. Mine does 4,000rpm at 70mph. But it is the lack of sound deadening and side windows that is worse. However, a pair of earplugs makes it heaven. Drove it 2.5 hours up the coast that way (and the same back). Very comfy.
The throttle bodies are worn and whatnot so I usually try to keep it at 3,000rpm minimum or else it gets a bogged down. Nice thing about cruising at high revs is no need to downshift to pass.
By the way, I got over 20 mpg doing that. 75mph average, 160 miles and plenty of hills.