You don't go much faster at 10k than FL250 since you are limited to 250Vmo.
Highest speeds are reached at 16-20,000' depending on temp. You are not
going to see 65GPH at FL190 unless you run at partial power which you never
do. I see 220lb/hr at FL280 (Marquise and Solitaire have -10 engines) but
even with the lower-powered -5 or -6 engines you won't see fuel flow that
low at FL190.

I entered a flight from SZT to PDX (which is 296nm) into FlightStar and it
says that it requires 794lb of fuel at 10K' and 674lb at FL200. To figure
out what the real economics are you need to decide how many people are going
and how much fuel you are going to take off with. You don't want to take
off with 1600nm of fuel for a 300nm trip unless the fuel price differencial
is huge. You will burn about 10% of the fuel that you don't need just to
carry it around and you will also climb and cruise slower which increased
your maitenance costs. I would focus on maitenance and fixed costs which
are much larger even in this era of $3 jet A.


Mike
MU-2








"Bravo8500" wrote in message
ups.com...
Thanks Mike.

I see that if you stay around 10k you'll go faster, but how much more
fuel does it cost you?

Say my fuel flow is 220/220 (~65 gph) at 19k, what would it be at 10k?