The effect weight has on performance is always evident. However, much depends upon the aircraft.
For example, the weight fuel and ammo in some aircraft makes a substantial difference in performance. For most American fighters, the weight difference can vary between 7% to well over 9%. This is certainly significant.
Here's some examples of optional fuel and ammo loads for some American fighters:
P-38L:
Full internal fuel and max ammo: 17,700 lb
50% fuel and reduced ammo: 16,098 lb
P-47D-40:
Full internal fuel and max ammo: 14,951 lb
50% fuel, 6 guns, 267 rds/gun: 13,161 lb
P-47N:
Full internal fuel and max ammo: 16,692 lb
50% fuel, 6 guns, 267 rds/gun: 14,355 lb
P-51D:
Full internal fuel and max ammo: 10,089 lb
50% fuel, six gun installation: 9,368 lb
50% fuel, four gun installation: 9,213 lb
F4U-1A:
Full internal fuel and max ammo: 12,904 lb
50% fuel and max ammo (no ammo options): 11,821 lb
Here's some Luftwaffe fighters for comparison.
Bf 109G-14:
Full internal fuel and max ammo (30mm): 7,253 lb
50% fuel and max ammo (20 mm): 6,823 lb
Fw 190A-5:
Full internal fuel and max ammo (4 cannon): 8,780 lb
50% fuel and max ammo (2 cannon): 8,167 lb
Note that the difference between weight of fuel is far more significant in the American fighters than in the German aircraft. Obviously, this is due to the huge internal capacity of the American aircraft required for long range operations.
To ignore these differences is to suffer an unnecessary loss of performance.
This is why it is often far better to take reduced internal fuel and add external drop tanks to get you to the fight, where they can be pitched off for combat.
Likewise, one should look at the ammo load and decide if lower weight options would be beneficial for the particular circumstances expected.
For example, to run out gas long before you can expend your ammo means that you were carrying more ammo or less gas than needed. There is certainly some need for basic planning.
For pilots who fly their aircraft to its limits, extra weight is an unwanted burden.
A typical load-out for my P-38J for a base attack sortie would be 50% internal fuel, one drop tank and one 1,000 lb bomb. Ammo load is usually 200 rounds per MG and the standard 150 cannon rounds. About the time I've used most of my ammo, my fuel state is such that I need to return anyway. The bomb is carried in the event a target of opportunity is discovered (GVs, buffs spawning or the VH needs a little attention). For base defense against GV attack, I'd take 50% fuel and two 1,000 lb bombs (I never take rockets on any P-38 as the drag penalty is excessive).
I'm one of those guys who likes to look for the sneak attack by GVs or an NOE. I then select the aircraft I deem is best for the situation and beat off the attack as best as I can. A skilled pilot in a potent fighter can tear an NOE to shreds. Against the NOE I prefer the SpitVIII or La-7. Against the GV mob, I'll fly whatever will work best.
Just remember, excessive internal fuel cannot be jettisoned like drop tanks or ordnance. Therefore, avoid taking too much internal gas, adding external fuel if needed.
My regards,
Widewing
