High Altitude Towing 7170

[ExcursionExpress]

Can you tell me more about the High Altitude tune?
My vehicle is a 2000 Ford Excursion 7.3L diesel. I will be towing a 7500 lb trailer from sea level to around 9000'.

Questions:
-What does the High Altitude tune do that is different from the towing or economy tunes?
-At what altitude should I change to the HA tune?

[willie]

It just has a little less fuel under heavyload fuel comand so it may smoke less , but if the truck is running good and does not smoke to munch you can probably stay with your current tune