My question does include the prop efficiency and I am not interested in how
they measure the output so much as what the actual output is. Input is easy:
volts x amps/746 gives the input hp. I am sure magazine reviews don't do
such testing, but I would sure expect a manufacturer to know what the
efficiency of his machine is.

BS


"Richard J Kinch" wrote in message
. ..
Robert or Karen Swarts writes:

Anyone know the truth?

It would take a dynamometer to characterize the efficiency of these motors
on a test bench. If you mean to include the prop efficiency, you would
also need a thrust gage for in-the-water tests. Do the magazine reviews
actually go to such lengths?