What is the rpm sweet spot for highway driving

Exactly RRR. When I'm on the road, I'll go 4 mph over the limit and put the cruise control on. I have had people pass me up, then they would have to suddenly slow the hell down because a cop had radar going. Not me, just leave the cruise where it's at. No problems. When I'm on the highway, it ain't about getting there the fastest, not anymore. One stop by the cops, and there goes all your time savings from speeding. Just my opinion.