The trailer's capacity is controlled by the max gross vehicle weight of 80,000 lbs for trucks in most of the states across the United States. Small tanker trucks have a maximum capacity of 1,000 to 3,000 gallons, while large tankers have a maximum capacity of 11,600 gallons. However, the maximum capacity of a tanker truck depends on the density of the liquid being transported....Read more at: https://www.trailersoftexas.com/blog/how-much-does-a-tank-trailer-hold--25081