Well i'm in a Honda Prelude club, and supposedly the stock setting is at 5200RPM, but i've seen it engage at about 5,500RPM in other cars. It has a lot to do with the oil too, if you have a lower oil pressure, it seems VTEC takes longer to engage, and if you have low oil, it just won't engage at all. So it can be a little variable depending on your oil pressure. For most Prelude's though, 5200RPM is the sweet spot for VTEC to kick in. It does sound really good in all the 5th generation prelude's, but keep in mind that you burn oil AND gas when hitting it. I tried driving once hitting VTEC whenever i could, 110 miles on a tank of gas!!!! lol. It's hard to not want to hit VTEC, but just remember doing it tooooo much will wear your engine down faster and leave you with poor gas mileage and lower oil life. Also on a side note, VTEC will not kick in until your car is warmed up as well. i found a site that says its 5200RPM: http://www.epinions.com/content_252192067204It's in the 4th paragraph that starts with "With a 195hp...."