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sorry but it sounds like there is just a ton of bad information going on here. Hondas i-VTEC system does that, people think its voodoo but its really simple.
there are two types of i-VTEC I know of, and the first is designed for power. its a lot like standard VTEC, whick is a second, more aggressive higher lift and duration cam profile that engages above a certain RPM/load/throttle%. This is good, and is typically applied to both the intake and exhaust valves and you can really have a very smooth gas sipper untill you get on the gas enough to trip it on the big cam lobes. my 95ex civic had the non "i" version of this, and it would get 45mpg if you were nice to it, but I got down to 23mpg one time at full speed all the way to college one morning(found top speed too).
the other version of VTEC is only applied to the intake valves, and it has one valve always running on the "big cam lobe" and the other valve rides on a VERY mild cam, almost round, below 2200rpms. not sure if it's load dependant after that or not. so the engine effectively acts as a 12valve engine below 2200rpms (the other valves open enough to create a nice swirl for completer combustion) and then as a single cam profile engine after that.
the "i" in i-VTEC means that the cam gears are auto adjustable by angle, they can adjust to create the best power or economy for that load/rpm/throttle%/etc.
I belive all of these things can be adjusted via the programmable computer mofication (kpro) and/or the fully adjustable ECU (AEM makes one of these for about 2x the cost of kpro).
its common for the civics to have a 5500rpm vtec crossover (switches to big cam lobes) for full vtec
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