Originally Posted by
100LL
Oh ok, so noise, fuel consumption and temperature. As for the fuel consumption yeah I can see that in the Arrow POH how changes in prop setting adjusts fuel consumption most noticeably at the 55% power range which makes sense cause lower setting means lower fuel consumption. Looking in the Seminole's POH though, it only offers two fuel consumptions for each percent power setting; a best economy and best power rate for all RPM selections 2100 to 2400. Would it be safe to believe that fuel consumption change is negligible in this situation for any given RPM setting?
Also a toss up question, why wouldn't there be a 2200 RPM MP option for the 75% power setting on the Arrow while there is one in the Seminole?
My guess would be that while they were doing all the calculations for the charts, that in that range some engine limit was succeptable to being exceeded, (remember they always build in a safety margin). Id have to look back at the POH to see, its been a number of years since I flew the Arrow. Or it could be just a misprint in the manual...