If you could go back to WWII & change 3 vehicles...

[vonKrimm]

My three (in no particular order):

1.  Change Allison powered P-38s to RR-Griffin (Napier Sabre for the 38G I guess) powered P-38s, add/improve dive flaps to all models, change armament to 4x23mm Madsen (which were called for at 1point in design process) cannon & 4x .50cal ( 2 each in nose, 1 each in both wing roots).   

2.  Give M4 Shermans the Christie suspension, skip the 75mm M3 gun & only have 3" M5 & 76mm M1 guns installed (less those that came with 105mm how.), diesel powered only.  Would/could save many tankers lives.

3.  Modify the M3/M5 to accept a 57mm gun.  Then come forward in time & make HT model for AH! 

[Anaxogoras]

So this is a "change the allied equipment" game?

Why oh why would you use such a magical wish on the P-38, one of the successful designs of the war?  I'm not P-38 nut, but I'm pretty sure those Allisons were not the same as what the P-39 and P-40 had.

Here's my list:

1.  Instead of the .50 cal Browning, the Americans have the Russian UB 12.7mm to produce under license: a far more efficient aircraft weapon, it had half the weight for about the same performance (early American fighters in the war were underpowered).

2.  The XP-39's larger supercharger was retained so that its production variants were 400mph+ aircraft.

3.  B-17/B-24 gunner crews equipped with the AH 'n' key.

[Wolfala]

1.  A P-47 with an R-4360 - and keep the turbo system. Oh yea, and MORE ammo so I can shoot more of you down.

2.  An A-20 with R-2800s and about 1000 rounds more ammo in the nose. Delete the tail turret and put a 20mm stinger with 100 rds in the pooper section.

3.  Keep the V-1710 in the P-38, but throw the Turbo-compound version V1710‑E22 in. 3000 HP per side wet, 2300 dry. Need the insane climb angles and speeds.

[thrila]

I'll change 1 aircraft in 3 ways instead-

1) Throw a couple of merlins/griffons in the Westland Whirlwind, it could do 360mph with it's two peregrine engines

2) Increase iit's ammo load of it's 4 x 20mm from 60rpg to 200rpg

3) Increased fuel capacity i.e aux/rear tanks and the option to carry drop tanks

[Scherf]

4) Rads a la Mossie to create some space in wing roots for fuel

5) Fuel cross-feed

6) Fully-feathering props

[Mace2004]

262 with afterburners and speedbrakes.  It badly needs both.

[E25280]

diesel powered only.  Would/could save many tankers lives.

Type of fuel had nothing to do with the tendency of the early Shermans to burn, contrary to popular myth.  If they had all been diesels, all it would have done is guarantee a shortage of fuel for the US war machine.

[vonKrimm]

Type of fuel had nothing to do with the tendency of the early Shermans to burn, contrary to popular myth.  If they had all been diesels, all it would have done is guarantee a shortage of fuel for the US war machine.

Well the myth never would have existed then would it?

On your second point:  Distilling gasoline from crude oil actually yields less gasoline than if the oil were refined into diesel; it also uses more resources to refine gasoline than diesel fuel.  I fail to see how getting more from less would lead to a strategic shortage; point in fact, the US had a surplus of crude oil.  The US did not even buy all that was available from central/south america.  The only shortage issue was refining capacity; thus if more diesel was produced, then less refining capacity is used, therefore a strategic surplus would accrue in reducingthe refining of gasoline for the increase of diesel.

[BnZs]

Go get some condensate from your local gas well, boil the lighter ends off, there, you got diesel. The lighter ends that form gasoline have to have anti-knock compounds added. Its a crime that diesel is the more expensive...

Well the myth never would have existed then would it?

On your second point:  Distilling gasoline from crude oil actually yields less gasoline than if the oil were refined into diesel; it also uses more resources to refine gasoline than diesel fuel.  I fail to see how getting more from less would lead to a strategic shortage; point in fact, the US had a surplus of crude oil.  The US did not even buy all that was available from central/south america.  The only shortage issue was refining capacity; thus if more diesel was produced, then less refining capacity is used, therefore a strategic surplus would accrue in reducingthe refining of gasoline for the increase of diesel.

[BaDkaRmA158Th]

-Plays quantum leap theme song-

"oh boy.."

A p39 with clipped wings, super charger, bit thicker/longer wing and x2 .50's in each wing vs. slung under in gondolas.
Also ability to change out the 37mm with a .50cal machine gun with around 1,000rnd's of ammo.
Oh and two Dt's under each wing.

P47 with x2 .20mm in gondolas for added air to air / air to ground punch. (Have seen pictures of this )

P38 with x2 37mm in nose, x2 20mm on bomb rack x2 20mm gun pods on rocket racks.

Guns guns guns!

[1pLUs44]

throw a turbocharger and a 20mm into the P-39Q.

Maybe put the same engine as the P-51, and make the gun like on the P-63 so it could hold more ammo, put 2 .50s in the nose, and 2 more 20mms in the wing gondolas instead of .50s...

BUT, you said vehicles *sigh*

1. Put the M-26 Pershing into faster production.

2. Find a way to mass produce the German built Panther/Tiger instead of wasting time on the Panzers.

3. Put the IS-2 (JS-2) into Soviet Service in 1940... See how quickly the war woulda lasted THEN!

[Gabriel]

Ive sometimes wondered what an all HMG version of a Bf 109 or Fw 190 would be like,

like a Bf 109F-4 with 3 x MG 131 in the cowling and nose hub, or an Fw 190A with 6x MG 131s.

[Rino]

Type of fuel had nothing to do with the tendency of the early Shermans to burn, contrary to popular myth.  If they had all been diesels, all it would have done is guarantee a shortage of fuel for the US war machine.

Yepper, moving the ammo storage and using wet storage helped out alot.

[Anaxogoras]

Ive sometimes wondered what an all HMG version of a Bf 109 or Fw 190 would be like,

like a Bf 109F-4 with 3 x MG 131 in the cowling and nose hub, or an Fw 190A with 6x MG 131s.

Why?  The ballistics of the MG 131 were no better than the MG 151/20.  If anything the Bf 109F should have had MG 151/20s in the wings instead of the single hub gun.

[Bronk]

So this is a "change the allied equipment" game?

Why oh why would you use such a magical wish on the P-38, one of the successful designs of the war?  I'm not P-38 nut, but I'm pretty sure those Allisons were not the same as what the P-39 and P-40 had.

Erm.. IIRC same engine sans the turbo-supercharger.