ok.......................
That makes sense, in that it will maintain 40 in/hg upto 12k DH. What has me scratching, is why its rated at 200hp at SL and 215 at 12k DH.
To my mind it'd be generating 40 inches from S/L all the way to 12k, making it 215 hp all the way up.
Pondering what I am missing (apart from the req'd knowledge)