All of this has been gone over before. I did a pretty detailed post which I will repost here:
Battle over Germany, January, 1944
P-51B, P-47PreD-25, F4U-1, P-38J, Escort Ability vs. Me-109G and Fw-190A-8
This is a topic that should activate all the white knights out there.
I wanted to try to come grasp how these four aircraft would perform in the escort role over Germany against their German opponent. The F4U was thrown in because it was brought up as an aircraft that should have been built instead of the P-47 (and I think the P-51, too). First I wanted to define the requirements of an escort fighter for supporting daylight bombing of Berlin by B-17s and B-24s. This is what I determined was needed.
1. Range to fly to Berlin and back
2. Endurance to allow a meaningful combat time under enemy attack.
3. Equal-to or better capability of engaging enemy aircraft in combat at or above 20,000 ft.
The methodology I used to compare these planes were, 1) determine total internal and external fuel available each aircraft, 2) calculate fuel required to transit to target (approx. 600 miles) at 25,000 ft, 3) calculate fuel required to return to base (I used ingress fuel since I am lazy and probably didn't have this data. Still should be okay for comparisons), 4) calculate fuel available for combat, 5) calculate combat time at Normal Rated Power (NRP), 6) compare performance at 20,000, 25,000, and 30,000 ft. Since the data available was not all compatible between aircraft (it never is), some alchemy was required to generate fuel consumption at 25,000 ft. It all seems to pass the smell test.
Assumptions.
1) Flight profile goes directly to Germany, optimum cruise, engage defenders, fly directly home. Weaving over slower bombers is not calculated but obviously would reduce time in combat. Comparisons are still valid.
2) Combat is engaged over target area and external fuel tanks jettisoned at commencement of combat. Again, if engaged inbound to target, combat time would be affected, but comparisons are still valid. Combat time would also be affected if a pilot hangs onto his tanks (which I don't think would be wise).
3) Normal Rated Power for combat is used for comparison purposes (another one of my simplifying decisions). Mil and max power will affect the higher HP aircraft to a greater extent (for example, a P-51 at max will be using less fuel than a P-47 because of the HP difference).
4) External fuel is a variable for most aircraft. In most cases, external fuel was enough to make it to the target area. The only exception was the F4U, which had to use some internal fuel to make the target.
References here are:
1) Flight Operations Instructions Chart, P-51D and K,
2) Tactical Planning Characteristics & Performance Chart, P-47
3) What appears to be a P-38 Pilot Handbook showing fuel consumption,
4) America's Hundred-Thousand
5) Other sources
Information Key:
Internal fuel – Useable Fuel stored internally in the aircraft
External fuel – Fuel stored in jettisonable tanks
Transit Fuel – Fuel required to fly from home base to target area not including takeoff and climb
Return to base – Fuel required to return to home base
Fuel available at combat start – Fuel remaining after jettison of external fuel
Fuel available for combat – fuel remaining after jettison minus return to base
Combat time – Time to consume fuel available for combat at normal rated power
P-38J
Internal Fuel, 410 gal
External Fuel, 600 gal
Transit Fuel, 600 miles, 277 gal
Return to base, 600 miles, 277 gal
Fuel available at combat start, 410 gal
Fuel available for combat, 123 gal
Combat time at NRP, 35 min.
P-47D Pre -25
Internal Fuel 305 gal
External Fuel 410 gal
Transit Fuel, 600 miles, 261 gal
Return to Base, 600 miles, 261 gal
Fuel available at combat start, 305 gal.
Fuel available for combat 44 gal
Combat time at NRP, 16 min.
F4U-1
Internal Fuel, 351 gal
External Fuel, 175 gal
Transit Fuel, 600 miles, 186 gal
Return to Base, 600 miles, 186 gal
Fuel available at combat start, 340 gal (Note: internal fuel was required to be used for ingress after drop tank was empty.)
Fuel available for combat, 154 gal.
Combat time at NRP, 1 hour, 6 min.
P-51B
Internal Fuel 269 gal
External Fuel 216 gal
Transit Fuel, 600 miles 108 gal
Return to Base, 600 miles 108 gal
Fuel available at combat start 229 gal. Note: 85 gal fuselage tank used down to 65 gal for combat stability.
Fuel available for combat 121 gal
Combat time at NRP, 1 hr 14 min.
Performance at 20k ft. (B-24 Altitude)
P-38J
Airspeed, 410 mph
Climb, 3000 ft/min
Ceiling, 44,000 ft.
P-47D Pre -25
Airspeed, 402 mph
Climb, 1565 ft/min
Ceiling, 42,000 ft.
F4U-1
Airspeed, 430 mph
Climb, 2800 ft/min
Ceiling, 36,900 ft.
P-51B
Airspeed, 424 mph
Climb, 2915 ft/min
Ceiling, 42,000
Luftwaffe Opposition
Bf-109G
Airspeed, 399 mph
Climb, 3094 ft/min
Ceiling, 39,000
Fw-190A-8
Airspeed, 405 mph
Climb, 2400 ft/min
Ceiling 35,000 ft.
Performance at 25k ft. (B-17 Altitude)
P-38J
Airspeed, 415 mph
Climb, 2600 ft/min
Ceiling, 44,000 ft.
P-47D Pre -25
Airspeed, 435 mph
Climb, 2300 ft/min
Ceiling, 42,000 ft.
F4U-1
Airspeed, 424 mph
Climb, 1650 ft/min
Ceiling, 36,900 ft.
P-51B
Airspeed, 427 mph
Climb, 2600 ft/min
Ceiling, 42,000 ft.
Luftwaffe Opposition
Bf-109G
Airspeed, 420 mph
Climb, 2200 ft/min
Ceiling, 39,000 ft.
Fw-190A-8
Airspeed, 392 mph
Climb, 2,200
Ceiling, 35,000 ft.
Performance at 30k ft. (Top Cover)
P-38J
Airspeed, 415 mph
Climb, 1900 ft/min
Ceiling, 44,000 ft.
P-47D-20
Airspeed, 430 mph
Climb, 1300 ft/min
Ceiling, 42,000
F4U-1
Airspeed, 390 mph
Climb, 1,000 ft/min
Ceiling, 36,900 ft/min
P-51B
Airspeed, 441 mph
Climb, 2250 ft/min
Ceiling, 42,000 ft.
Luftwaffe Opposition
Bf-109G
Airspeed, 400 mph
Climb, 1625 ft/min
Ceiling, 39,000 ft.
Fw-190 A-8
Airspeed, 386 mph
Climb, 1080 ft/sec
Ceiling, 35,000 ft.
Observations:
P-38J
Very good range with average time in combat.
Competitive performance with opposition. Generally superior climb rate.
Good high altitude performance, excellent ceiling.
P-38 would probably be an effective escort with capable pilots
P-47D-20
Limited range, poor time in combat
Performance limited at 20k, much better as altitude increases
Very good high altitude performance.
P-47 effectiveness limited by range. Later P-47 versions solved this problem, especially the P-47N, with larger internal fuel capacity.
F4U-1
Excellent range, excellent time in combat
Capable performance at lower altitudes, suffers at high altitude, low ceiling.
F4U would suffer in escort duty due to lack of high altitude performance. The aircraft would have needed the -18W engine to adequately perform at the higher altitudes, this engine was not available until mid to late '44. Turbocharging was probably not an option. The F4U-4, available in May, '44, alleviates the high altitude performance problem, but reduced internal fuel would hamper escort ability.
P-51B
Excellent range, excellent time in combat
Comparable performance to opposition at 20k, outperforms Bf-109 and easily outperforms Fw-190 at 25k. Easily outperforms both at 30k.
The P-51B was most likely the most efficient propeller aircraft in WWII. Its speed/hp at SL is .246 mph/hp. Comparison to other aircraft, P-51D is .23, Fw-190D-9 is .217, Ta-152H is .18, F4U-1 is .162, and the P-47B is .15 (note that the F4U-1 is slightly more efficient than the P-47, which is reflected in the range numbers even though they have roughly the same engine). The efficiency of the P-51, combined with a moderate internal fuel load, and very good high altitude performance is the secret to its supremacy in the escort fighter role.
Bf-109G
The Bf-109 has some good climb characteristics but suffers in airspeed. In general, it is somewhat competitive up to 25k. It is outperformed by the AF escort fighters above 25k.
Fw-190A-8
Except for the P-47 at 20k ft. and the F4U, the Fw-190 has significant performance shortcomings to the escort fighters at these altitudes.
At the altitudes where the bombers flew, except maybe the B-24, the Luftwaffe fighters had performance shortcomings, especially with the P-51. January to June, '44 was a critical time for Germany, being pressured by the Russians on the East and D-Day being prepared on the West and with ever increasing bomber formations over the homeland. The Germans were not able to adequately contend the airspace above 20k ft. until the advent of the Bf-109K and the Fw-190D-9 in late '44.
So, gird your loins and do battle with what I have presented and point out errors, which is possible, in my logic and/or data.