But that’s at 70% power. Low economy is not 70% power.
Yes, that would correspond with the chart above. There a max range of 740 miles is estimated at around 27 MAP and 2200 rpm yielding 220mph
So I guess the BR P-40 might be leaking somewhere 
It would be nice if someone from BR could weigh in on this…….
I made some tests today at 9,000 ft. We are actually not far from the POH.
I used the max fuel load of 170 gals for calculating the endurance. The last two rows are endurance in hours and endurance in nautical miles.
I calculated TAS from IAS, then gallons per hour and from that the endurance.
MAP 19 at 1950 RPM gives 150 mph IAS only, that’s not doable. Everything else works and we have an endurance of nearly 700 nm.
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Thanks for clearing that up and testing.
But what for you mean by not doable? Is 150mph IAS too slow to stay airborne?
It flies, I’m just not feeling ok at that low speed.
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Yeah, unlike in a car, speed equals safety when you’re in a fixed wing plane
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Gents,
Have tried to search …but opinions on Big Radials P40 or Inibuilds P40.
Cheers and Beers
Today I did a new test of the fuel consumption and range. I did a round trip from FWSU to a location 160 nm west, made a U turn, and then returned to FWSU. After the U-turn while passing the waypoint I magically refuelled the aircraft. Then I kept altitude, speed, and engine/propeller settings until I overflew FWSU again.
Altitude: 17000 feet
MAP: 23 inches
RPM: 2050
(Comment: I chose to go a bit higher than the figures in the performance chart. That was so as to keep the altitude and maintain a decent speed. With the settings in the chart and at 18000 feet I couldn’t really hold altitude without dropping below about 140 miles per hour.)
IAS: 170 miles per hour
Distance flown: 160 NM
Fuel used: 41.23 gallons
With a total fuel capacity of 169.4 gallons this would give me a range of just under 660 NM. I had a couple of knots of headwind so let’s round this up to 670 NM. According to the chart the range should be somewhere between 740 and 870 NM.
However, this measurement intentionally didn’t contain any take-off and climb. The P40 gulps down fuel during those phases of flight so the real range would be a bit smaller.
From my point of view this concludes my tests and I’m pleased with the outcome. The discrepancy between my measurement and the official chart is not altogether unreasonable, especially considering I’m still a rather poor pilot and certainly don’t manage to squeeze out the very best performance. For instance, I guess some better rudder trim and a steadier hand on the stick would have reduced drag and track miles ever so slightly.
I’m glad I did these tests, they were great fun and something I hadn’t done before. It also provided me with the opportunity to see the world from higher altitudes as I otherwise rarely exceed 10000 feet. To me the P40 now feels even better than it did before. I even feel like I’m learning to keep her under control during take-off and landing.
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Might also want to take a look at these two documents as well.
Granted, this is for all models of P-40, but should be somewhat relevant to the B/C
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They’ve been yelled at too many times for doing support here. You’ll need to go to their discord if you want to hear what they have to say on the subject.
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yes - please go to their discord server to log your squawks - even if its just to link to this board so you don’t have to retype it. Just please be cordial
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Yeah, they’d probably appreciate seeing the tests y’all have done, but with MS’s “no official support” policy, this isn’t the place to query about the fuel consumption.
I find Discord annoying AF as a forum substitute (it’s fine for voice chat in games), but it’s the venue of choice nowadays so I grudgingly use it while wishing they’d hire me to redo their user experience. 
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Well, it’s good to discuss it here with everyone, too. Just don’t expect a response from the development team. They do read here, however. And I’m sure it’s hard for them to not respond, lol 
(no sarcasm)
In a climb to 10,000 ft and subsequent descent the P40 needed 35 gallons. On approach with the drag of flaps and gear it consumes a lot of fuel at a low speed.
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Huh, that’s even more than I thought. That explains why this latest test rendered such a longer range compared with my earlier tests. Quite interesting. If she consumes this much to 10000 feet, how can she ever (in real life) reach 20000 and stay up there for more than a few minutes?
They don’t. One issue with the P-40 was, because of the USAAF felt at the time of specification was that they needed low altitude interceptors only, was they didn’t include a supercharger (or turbo-supercharger) as in the P-47, P-51 and P-38 making it a low altitude fighter. Yes, it could get to 20,000 ft, but it really didn’t like going above 15,000 ft.
interestingly - the P-47 was designed by Seversky around the Double Wasp 2800 radial and supercharger - the same powerplant and aspirator as the B-17 - specifically for high altitude LONG RANGE bomber escort duty. It had the range because we know they were flown across the Atlantic from the US factories to England. It was LeMay and the ‘bomber mafia’ that wanted to prove that the American bomber force was so well armed and ‘fast’ that it didn’t NEED fighter escort. When the daylight bomber squadrons were decimated in the first few months of operations, rather than admit they were wrong and that those crews were lost needlessly - the USAAC brass claimed they didn’t have suitable fighter escort aircraft - that the P-47 didn’t have the range for the job. It wasn’t true - but it allowed everyone involved in the original mistake to save face. The P-51 was looked upon as the savior of the daylight bombing campaign and the rest is history. The truth is - the P-47 with the pancake centerline tank and two wing tanks could easily cover the bombers to the same altitudes, distances and durations as any other escort fighter…and could do it in 1942 !
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All P-40s with the Allison engine had a single speed, single stage supercharger.
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Interesting post! Just one small correction, the B-17 was powered by Wright Cyclone R-1820’s.
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