the cost index isn't just a number to play with guys.
The best thing is to insert the wind and try to feed the computer the best you can.
The company will calculate a Cost index which suits you the best.
What matters saving 200 KG of fuel when you fly 3 minutes longer on every flight and thus exceed engine wear limit more early and engine time limited parameters?
Cost index isn't just Fuel Time. Itīs also about engine overhaul, salary, and stuff.
We need to accept that we aren't more intelligent than the CostIndex.
Whats important is that your company has a good fuel saving and performance Team calculating all this. Our company thought about reducing the thrust reduction altitude to 800ft but then they faced the problem that the government wanted to implement noise bills for actual measured noise. And at this part it would've been more expensive to reduce thrust on A320 at 800ft AGL than 1000ft.
The last month we flew with 50, quite fast, and as your speed is high you get a different number for arrival and more often get directs. but yeah on descends I always modified the speed down to have some buffer.
So talk to your performance staff, do fuel saving courses, and stop trying being more intelligent than the airbus.
For example all people switching the Vent blower off. How often do i need to reset that !!!! and how much delay do we produce to such small things... The Vent Blower button and Vent isn't made for switching on off that often...