[n86121]

From my excruciating review of TCM manuals,
interlaced into T337D performance charts...

75% ROP will give around 150knots IAS @ 13.3gph (ea) x2 = 26.5 gph
65% LOP will give around 140knots IAS @ 10.3gph (ea) x2 = 20.6 gph

In the turbo, (non-pressurized) TAS increases linearly @10 knots/5k ft

Until you hit 25k (critical altitude), when engine poer starts to dropoff
I've never taken it that high, that's a looooong way down if you want to stop!

So for example, at 10k ft

TAS 75%= 150+10x2=170k @ ROP = 26.5.3gph = 6.4 kn/gal
TAS 65%= 140+10x2=160k @ LOP = 20.6gph = 7.7 kn/gal

= 20% more range/gal = 6% reduction in TAS speed.

=====

Applied to my theoretical 1400 kn trip (each way) from Wash DC to Denver and back... 2800 miles total...

75% = 2800/170k = 16.5 hrs @ 26.5 = 440 gals
65% = 2800i/160k = 17.5 hrs @10.3 gph (ea) =360 gals

For ~80 gals extra (roundtrip ~$500?) ...I can cut the round trip time by just ~1 hours...?

Questions become,

1) Am I willing to pay $500 to get an hour of my time back? ...nah, I'll just enjoy the cruise for another hour

2) If the airplane costs $200/hour (??), one less hour reduces the extra fuel cost by $200....

CONCLUDE => It does seem to suggest LOP at 65% and enjoy the extra hour of flight time...

Thoughts?