I also have a question regarding TOPCAT;When I set up all my fuel loads and payload and then go to the take off page to see how far I can derate. Even though TOPCAT says setting an assumed temperature of just for example lets say 46 should give 86% power, in the NGX it shows something like 89 - How do I configure this correctly?I'm flying the 737-700 Winglet model BTWThanks,James

First, make sure you are on the same page with engine rating - since TOPCAT calculates values for 7B22s, it is one derate lower, aka TO-1 in TOPCAT equates TO-2 in PMDG NGX.Also make sure you compare the bugs only after your engines are running and all is configured for take-off - the FMC recalculates RPMs depending on stuff like anti-ice, bleeds, packs etc. being on/off.