On Monday, September 23, 2019 at 6:55:24 PM UTC-4, waremark wrote:
Have you confirmed for each whether or not they are using total energy arrival height, ie including the expected height recovery from pull up to best glide height? That could easily account for a difference of 400 feet.

Is the difference a fixed value regardless of distance to go, rather than a percentage?

Have you checked whether the elevation of your arrival airfield is set the same in both devices?

It's either a user set up or database problem. There's no other likely possibility.

OT... but using a preset margin is sooooo 1986. Set the margin to zero and let the device tell you your predicted arrival height. If you don't like the numbers you see, do that PIC thing....

T8