89 octane OK in 2.8L V6?

[BOEING377@aol.com]

The manual says use only high octane gas (92 or higher).  I tried 89 and no
knocking was detectable.  Am I getting less power or hurting fuel economy?  Is
the knock sensor retarding the timing or does the car run fine on this lower
octane?  I don't do hard acceleration normally, but even when I did I couldn't
detect any knock or loss of power with a tank of 89 compared to perfornmace
with 92 octane.  Comments?  Mark,  92 100S 86K