Originally Posted by
A37575
Zero thrust on light twins is not always easy to set because it varies and any variance from the correct setting at the time could either give you an optimistic rate of climb or no climb at all. Few POH state the combination of RPM and manifold pressure setting for zero thrust which means it is a matter of guesswork - such as "my instructor told me'
This is a very good point and IMO most of the time the "training zero thrust" power setting is actually more than zero thrust thus giving the student a false confidence the actual ability of the aircraft to climb after a real engine failure.