Now that I cannot confirm... vanos controls the intake to such a degree that it will help "improve performance" both in HP figures and in fuel consumption by adjusting the whacha-ma-call-it. At least according to BMW.
Oh, and btw, a new vanos control unit, alone, will cost you $630 in parts, tack on another $500 for install (and those figures are on the cheap end assuming of course you can even install that on it. I know because my E46 had a faulty vanos.
Dough