737 - Combining derate and assumed temp?
Assuming that your operator allows for the use of an assumed temperature, with a derate. How do you determine which combination to use?
For example:
Let's say that the OAT is 0 ºC and after consulting the RTOW tables, you determine that the following are possible:
Full rated - Assumed temp=44 ºC
24K (TO-1) - Assumed temp=36 ºC
22K (TO-2) - Assumed temp=15 ºC
How do you know which combination will be the most efficient, or will provide the least amount of engine wear?