And presumably until you get around to finding this hypothetical object, HTC should ignore my evidence and leave the speed at 20 mph? You are grasping at straws here. The OP is a reasonable request, based on reasonable available evidence, and is not in any way a game changer. The Firefly will still be the slowest tank in the game, and the world will not come to an end.
Deacon, I don't know what you're going on about. I certainly am not attacking you (I already said that), but trying to get to the bottom of where HTC got their numbers. They don't normally tell us. What I have been doing, and presumably Butcher, is discover the reason HTC has it as they do. I'm afraid you don't understand that the evidence I found suggests you are wrong about the IC, but correct about the VC. The IC has the Continental 975 rotary engine, which has 70 HP less than the VC. Otherwise, it is the same tank with the same mods, except that the VC also had drive train modifications performed upon it to prevent breakdowns.
As to your claim that the performance in AH is "wrong," I have found no reason to support that it is "right." In other words, at this point I agree. Also what you didn't follow is, what I did was take the performance of the IC and the mechanical efficiency reported in the US Army Technical manual for the drive train, and add the 70 additional HP the VC has over the IC, and what results is the 22.25 mph. The drive modification is not speculation. If Hayward did not report that then he doesn't do a very good job of reporting the history of the Firefly. I know about the mechanical problems because they are reported in Fletcher's book "Sherman Firefly," which you can pick up at Amazon for not much coin (I think Kindle is less than $10). You might also look at "M4 Sherman at War," by Michael Green and James D. Brown.
The reason I want to look at the British field manual for the VC Firefly is it will tell you exactly what the tank can do. Also, one thing you are wrong about is on-road versus off-road performance. HTC is correct in allowing the tanks to perform on open ground at the same speeds that the tanks provide on road. That is very clearly stated in the Technical Manual for the tank. I'm sure there are circumstances where off-road speed were less, such as when the ground is loose gravel piles, or loose topsoil, but on level, firm ground there is no reason the tanks would be slowed down.
I'm also not suggesting that HTC should ignore your wish. Only they know the evidence they used in creating the VC, and only they can decide. If they have in their hands the British Field Manual and it reports 20 mph, then you won't see any change made.
EDIT: One of the problems with retrieving information from the Ordnance Museum, at the moment, is the budget cuts. The Aberdeen museum has been relocated to Ft. Lee, but the money for the museum that would be built there has not been approved, and won't be until something happens. That means the Tiger I that only just returned from Germany is an open air display, as are all displays like 'Anzio Annie' and other very unique artifacts of the war. There is a Heritage Center, but no enclosed museum, so where you call or write for archived information is your guess.
