Published 05 November, 2020; last updated 10 December, 2020
The North American P-51 Mustang:
The North American P-51 Mustang was a 1940 US WWII fighter and fighter-bomber.1
According to Wikipedia2:
We use the range 3,465—5,488 kg, since we do not know at what weight in that range the relevant speeds were measured.
Wikipedia tells us that cruising speed was 362 mph (162 m/s)3
A table from WWII Aircraft Performance gives combinations of flight parameters apparently for a version of the P-51, however it has no title or description, so we cannot be confident. 4 We extracted some data from it here. This data suggests the best combination of parameters gives a fuel economy of 6.7 miles/gallon (10.8km)
We don’t know what fuel was used, but fuel energy density seems likely to be between 31—39 MJ/L = 117—148 MJ/gallon.5
Thus the plane flew about 10.8km on 117—148 MJ of fuel, for 0.073—0.092 m/kJ
This gives us a range of 0.25 – 0.50 kg.m/J
Primary author: Ronny Fernandez
“North American P-51 Mustang.” In Wikipedia, October 19, 2020. https://en.wikipedia.org/w/index.php?title=North_American_P-51_Mustang&oldid=984347874.
“Energy Density.” In Wikipedia, September 21, 2020. https://en.wikipedia.org/w/index.php?title=Energy_density&oldid=979608484.