It depends on what the job is, small airway service trucks for light aircraft hold around 450 - 700 gallons and those road monsters can move 9500 Gallons in a single 4 compartment aluminum tanker -...
Any where from 6,000 gallon up to 8,000 gallon depending on the product loaded it's more a matter of legal gross weight can not exceed 80,000lbs for a 16 wheeler
Ammonia in a gaseous state would be measured in cubic feet. Ammonia tanker trailers would be sized based upon how many gallons of liquid ammonia they could legally carry in the state/states in which...