Ran across this study of the Lockheed 10 E Airliner for long range use (normal range was 600-800 miles), 4000 miles or more.
http://tighar.org/Projects/Earhart/Archives/Documents/Report_487/Report487.pdf
Normal Gross weight was 10,500lbs.
They made calculations for 16,500 lbs with 1200 gallons fuel on board.
One chart shows optimum cruising altitude did NOT exceed 1000ft until 1000 miles had been flown and about 2000lbs of fuel used.
A number of planes made long range record flights. But they were operating in severely overloaded condition at take-off (Lockheed 10 at 16,500lbs needed the same take-off distance as a B-25 at 36,000lbs) and for a considerable number of miles into the trip.
The
fact that plane XXX made a record flight of YYYY miles/km doesn't mean it could do anywhere near that in military service.
The Lockheed 14 Super Electra was used for several record setting flights, While it's service as the Hudson with roughly comparable engines was certainly worthwhile it was NOT considered a
long range patrol plane.