"Michael Pilla" wrote in message
...
[...][flush BYB] ===========
Every Mooney I have flown has always gained an inch with filter bypassed.
I
don't have my manuals or logbook handy, but I recall that the POH
indicated
an inch gain. The models were older Mooneys: M20(F?, don't recall) and
M20J.

YMMV.

Michael Pilla

At altitude no big worry about dust and bugs, I wouldn't think. However, in
Missouri where there's lots of particulates and airborne effluvia and
pestilence, I would always filter the air.