its ok man, I'm assuming by your screen name and 4500rpm you have a b18c1 so thats ok dude, you're not in full throttle yet either until 5700 or so when the secondaries are wide open. I use to be in vtec all the damn time on the highway coming home from work (smyrna to gwinnett) which its ok, just a little more gas consumption and maybe a tiny bit of oil, but other than that you're good. Now if it bothers you that much just replace the intake manifold with a single stage manifold i.e. skunk2, blox, aebs, etc. But if you do replace it then don't forget to replace/chip the ecu so it'll run right, The p72 will run like straight shit on a single stage manifold so some tuning is suggested but not required, mainly because the fuel curve/timing is changed when vtec is altered i.e. vtec was set at 5500 but you changed it to 6k then the fuel/throttle or what not needs to be changed to match the vtec engagement. Sorry if this doesn't make any sense, I'm just used to working on a v-afc so much.