wrote:
Useful load probably won't change that much
but PAYLOAD should get a nice bump up because the diesel's lower SFC means
less fuel will be needed for a given mission, even taking into account that
diesel fuel (which is essentially the same as Jet-A) is slightly heavier (in
lbs/gal) than gasoline.

Actually in this discussion, the density of the jet fuel isn't a factor
because BSFC is based on weight, not volume. Diesel engine has a lower
BSFC means it needs less weight of the fuel to produce the same amount
of power.