Found some interesting info on the P-40 vs the Zero, with a former AVG guy, Erik Shilling: Flying Tiger...
Kinda long but a good read...
The P-40B (Tomahawk IIA) flown by the Flying Tigers had. . .
Self sealing fuel tanks. . . Japanese aircraft had none... Armor plate that would stop any bullets fired from a Japanese fighter... Bullet proof windshield that would stop any Japanese fighter's machine gun bullets... Very much stronger than the flimsily constructed Japanese aircraft...
A number of Zero's shed their wings at speeds slightly over 350 mph... Japanese would not even attempt a dive that approached 350 mph...
None of Japan's aircraft could even stand up to P-40's .30 and .50 caliber guns... It only required a few incendiary bullets, even from our .30 cal. guns, to set fire to, or explode their aircraft...
Although subsequent model P-40s did fall behind the newer model Me.109s and British Spitfires, however in every case, each new model Zero that came out remained inferior to its contemporary model P-40.
Now why in the hell would anyone consider the Zero to be the best fighter of the war?
Hell, it didn't even start out that way. . .
The above is not just my opinion, but garnered from available facts, and flying the P-40 in combat.
What was truly obsolete happened to be the turning or dogfighting combat that had been used during of WW I.
The most dangerous problem:
Although avoidable, possibly the tumble the P-40 would get into if stalling in an extreme nose high attitude... It would start a tail slide, finally swapping end for end and go into a tumble taking as much as 12,000 feet to recover... Frank Shield got into a tumble while we were having a dog fight... Frank had to bail out.... He had not recovered control while only a scant 2000 feet still in a vertical dive... He entered the tumble at 10,000 feet...
Thoughts on the Japanese pilots:
Japanese pilots were highly disciplined... Damn few were up to the standards of our pilots graduated from the American military school in the states...
However, most Americans were using the wrong tactic through no fault of their own... Combat in all theaters turned in our favor, improving considerably once this was overcome...
How did the P-40 compare to the Japanese Zero:
Of all the fighter planes flown against the Japanese, the P-40 was the most under-rated airplane and the Japanese Zero was the most overrated.... Contrary to popular belief, the P-40's larger turning radius did not present a problem when understood, and proper tactics were used against the Japanese fighters.... Also its lower rate of climb could easily be overcome...
The P-40 which was more than 40 mph faster than the Zero, could still climb at a speed that the zero was incapable of attaining... Pilots that tried to dogfight lost their lives... Whereas the hit and run tactic with a faster plane was the only way to fight the Hayabusa or Zero...
Erich Hartman, Germany's leading Ace with 352 victories said, "I always avoid the turning combat when ever possible. "In half of my victories," Hartman said, "the pilot was unaware he was under attack until he was being hit..." Hartman averaged 70 victories a year... Therefore, why is it so difficult for some Americans to believe that 82 AVG pilots destroyed 297 Japanese in a seven month period???
To put our victories in their proper prospective: If all the AVG pilots had been of Eric Hartman's caliber, we would have destroyed 3,052 airplanes in this 7 month period... Provided there had been enough Japanese airplanes available to shoot down... Now, 296 doesn't seem so terribly outstanding, as a matter of fact somewhat shabby...
The P-40s was 50 mph faster than the Hayabusa we called the I-97...
The P-40's top speed was 70 mph faster than the I-96, an early fixed geared Mitsubishi...
The P-40 was 130 mph faster than the Japanese bomber, and 130 mph faster in a dive than any fighter the Japanese had...
The P-40's pilot protection was in the form of self-sealing fuel tanks. Almost two - inch thick bullet proof armor plate windshields, and 9 mm and 7 mm armor plate protecting the pilot from behind...Also the P-40's armor plate could stop the bullets from any military aircraft the Japanese had in the China - Burma theater...
The most irritating:
One author, writing for the Smithsonian's Air Space magazine claims, "The Zero to be the most fabulous fighter to come out of the war..." Those making such statements are ill informed... They either never flew the Zero, never fought the Zero as it should have been, and most likely are not pilots, nor aeronautical engineers, so how the hell do they know...
Aviation buffs always come up with the statement that the Zero was more maneuverable than the P-40... Emphatically not true... Flown properly the P-40 was an outstanding fighter, especially in the Chinese theater of war...
Actually the P-40 was more maneuverable than the Zero... Unfortunately, those that claim otherwise do not know the definition of maneuverability as defined by Webster's dictionary...
1. To perform a movement in military or naval tactics in order to secure an advantage...
2. An intended and controlled variation from a straight and level
flight path in the operation of an aircraft...
3. To make a series of changes in direction and position for a specific purpose...
4. Evasive movement or shift of tactics...
5. To manage into or out of a position or condition...
6. To bring about or secure as a result of skillful management...
Interesting comments by Saburo Sakai about the Zero:
In a short but informative interview with Saburo Sakai, Japans leading living Ace, I asked, "Commander, what was the Zero's top speed?" His answer amazed me when he said, "The A6M2 had a top speed of 309 mph, and a maximum allowable dive speed of 350 mph... It became extremely heavy on the controls above 275 mph, and approaching 350 mph, the Zero's controls were so heavy it was impossible to roll... A further comment by Sakai was that the skin on the wings started to wrinkle, causing the pilot great concern, since a number of Zero's had shed their wings in a dive..." A captured Zero tested by Americans military, showed its top speed to be 319 mph, this was a later model, the AM6M5, and was tested without guns or ammunition... Therefore Saburo Sakai's statement that the top speed of the A6M2 and A6M3 of 309 mph would seem to be correct...
Saburo Sakai, in an interview made on August 11, 1996, admitted that, after flying the P-51 he had changed his mind and now rated the Zero as number two, where as before he thought it was the best... He said, "the P-51 could do everything the Zero could do and more..." My comment to him would have been that it's too bad you never got the opportunity to fly the P-40...
Compare this to the P-40's 355 mph, and he the maximum allowable dive speed of 480 mph, (occasionally our pilots dove as fast as 510 mph) 130 mph faster than the Zero... The P-40's roll rate at 260 mph was 96 degrees per second, three times that of the Zero's mere 35 degrees at the same speed...
What proof is there that the AVG, in the beginning of the war, was the only outfit using proper tactics?:
The Americans were still using the suicidal "Dogfight," or turning combat... When the Lockheed P-38s were first introduced into the Pacific theater in 1943... Saburo Sakai says, "The Zeros were shooting them down in large numbers..." Although the Lockheed had a 100 mile per hour speed advantage, this is what happened when the airplane wasn't being used properly... Saburo further states, "When the Americans changed their tactic, the Zero pilots became fearful of the P-38, because they were decimating the Zeros..."
As early as September 1941 Chennault was teaching us to hit and run, requiring speed, which was the P-40's forte against the Japanese... When properly used, it outclassed the Japanese Zero in every respect... It took the American Military 2 more years, and the loss of several hundred American pilots, before they stumbled on the secret of successfully fighting the Japanese in the air...