Seems to be significant RPM creep over the last few years. DifferentPointOfView's jeep it is a 95 model with likely an I6, I still firmly believe him when he says 3000. You are right on the suburban, I am very much out of touch with new vehicles and what I said applies better for vehicles from a decade ago:
http://media.gm.com/us/gm/en/news/events/pig_index.html