|
It seems this is a largely theoretical discussion, in that you're discussing the optimal means of descending a hill in which:
1. The slope is gentle enough that the PSL (or other maximum speed determined by driver) won't be exceeded by gravity.
2. Hill.has no steep curves/switchbacks.
3. Hill has no traffic-control devices at bottom that would make momentum conservation moot.
4. Vehicle is equipped w/ DFCO and is observed to engage for the lenght of the hill.
So YES, in this very special case of a "perfect" hill, coast in neutral. For most "real-world" hills, leave it in gear (DFCO) and get less fuel burn, "free" alternator and accessories, less brake-pad wear, etc.
__________________
|