As most of us know, in addition to the towing capacity, the payload or cargo capacity is just as important. I've seen several people indicate that you need to subtract the weight of a full tank of gas from your payload/cargo capacity but that seems contrary (at least in Ford's case) to what they indicate.
For example, in the manual it says to subtract "Hitch hardware weight, such as a draw bar, ball, locks or weight distributing, Driver weight, Passenger(s) weight, Payload, cargo and luggage weight Aftermarket equipment weight"
It does not specifically mention to subtract the weight of a full tank of gas which goes along with what it says in Ford's Truck Payload documents such as this one:
It states the base curb weight is "The weight of the vehicle including standard equipment, oil, lubricants and a full tank of fuel. It does not include the weight of driver, passengers, cargo or any optional or aftermarket equipment."
If the weight of a full tank of gas is already factored in, why would one need to subtract it again from the payload/cargo capacity? Isn't that double dipping?
I can't speak for GM or Dodge but that appears to be the case for Ford.