'really high' doesn't tell us anything. Post the RPMs corresponding to a few MPH set points, such as 30, 50, 60.
Ok basically what happens when I start my car it sits and revs up and down between 500 rpm and 1500 rpm until it warms up and then as I'm driving down the road going 50 mph in fifth gear my rpms sit at 3200 rpm and when on the highway going 70mph my rpms are at 4000 rpm