And don't forget, sometimes it just doesn't matter (the filter).  I have a
factory rebuilt engine, with 25K on it, Mann filters, 20W50 in SF, and I
still get the exact same buzzer at the same time (deceleration on off ramp,
and also under load at low RPMs uphill).
bmc  :)
"Faith will move mountains, but you'd better bring a shovel...."

 Also, many folks on this list (air and
> water) feel VERY strongly about using only OEM or MANN oil filters.
> Though I don't share their zeal, it is a widespread conviction worth
> noting.
>