Check'optimum'alt on Prog page.See what it says is Opt' with your present weight/temp'
Select 'Airspeed'modify your cost index(go lower to 10,from 30)in 'perf' page.Rechck your 'Opt' on prog page-to see if it improves your 'opt' with lower C/I...If it don't improve-stay where you are!! If it improves with the lower C/I,your in the ballpark.I've been in the temp' squease too many times to Just go,without any other guides.