A quick follow-up to show relative performance between the P-38J/L and the P-51B and P-51D. All performance figures represent WEP use and 25% internal fuel, zero burn.
First we have max speed at sea level... Both P-51s are considerably faster than the P-38s. Typically 359 mph and 366 mph respectively for the Mustangs, with 344 mph for both P-38s. In many situations, the P-51s can unload and extend away from the P-38s.
Advantage, Mustangs.
Acceleration from 150 mph to 300 mph favors the P-51D by a tiny bit, with times measured at 45.31 seconds for the P-51D and 45.47 seconds for the P-38J. From 150 to 250, the P-38J accelerates faster. However, the far lower drag of the P-51D comes into play as speeds increase and it hauls in and passes the P-38J just before 300 mph.
Advantage, dead heat.
Climb was measured from 1,000 feet, climbing to 5,000 feet beginning at 180 mph TAS.
P-38J: 56.82 seconds/4,223 ft per minute average
P-51D: 66.16 seconds/3,628 ft per minute average
Advantage, P-38J
Turn radius and rate of turn.
No flaps.
P-51B: 764 ft @ 18.5 degrees/sec
P-51D: 771 ft @ 17.0 degrees/sec
P-38J: 865 ft @ 16.9 degrees/sec
Advantage, Mustangs
Full flaps:
P-51B: 610 ft @ 16.7 degrees/sec
P-38J: 616 ft @ 18.7 degrees/sec
P-51D: 624 ft @ 16.7 degrees/sec
Advantage, P-38J
As you can see, advantages go back and forth.
One final thought. I have been saying ever since update 2.07, that there was no value to be gained by using more than two notches of flaps in a P-51. Adding more flaps produces minor reduction in turn radius, but huge loss of turn rate. Turn rate is, IMHO, more important than turn radius.
An example of this is the P-51B. With just two notches of flaps, it generates a turn radius of 754 feet, but its turn rate is nearly 19.2 degrees per second. Note that the P-51s can get two notches out before the P-38s can even begin to lower flaps. That's a significant, but short-lived advantage for the P-51s.
For the P-38J, using full flaps actually degrades turn radius a bit, and really kills turn rate. I'd not use full flaps for dogfighting, except to dump speed to force an overshoot.
My regards,
Widewing