No, the 800# increase in TV GVW is not a measure of the TW.
The estimated 90# of gear and 55# of WDH added to the TV after the first weighing makes the TW appear to be greater than actual.
The estimated 100# of fuel not included in the second weighing makes the TW appear to be less than actual.
The amount of load transferred to the TT's axles via the WDH makes the TW appear to be less than actual.
You cannot calculate the TW using only the information provided, because the amount of load transferred to the TT's axles is unknown.
If the weight of gear and WDH which was added and the weight of 2/3 tank of fuel which was removed is properly accounted for,
the indicated increase in hitch load is 800-(90+55)+100 = 755#.
However, the TW is not equal to the increase in hitch load.
The TW is equal to the increase in hitch load PLUS the amount of load transferred to the TT's axles.
The amount of load transferred cannot be determined from the information provided.
Therefore, the tongue weight cannot be determined from the information provided.
Ron
Regardless what the transfer weight is that is his tongue weight... If he disconnects the WD he will just get his TW without WD.
Example: My tongue weight with WD active is 340. Without 420. Im transfering 80 lbs to TT..
The transfer dont matter much really. If I do the math of truck alone minus TV, and TT with WD activated I get the same # 340.
So not understanding what your saying...
I understand that adding or subtracting more weight changes things, but at least its a base line with all his gear....
