With Ram 1500 trucks there is the option of ordering the truck with a 33 gallon gas tank. With Ford F-150 there is the option of getting a 36 gallon gas tank. Toyota Tundra trucks come standard with 38 gallon gas tanks. It is only with Chevy 1500 trucks where a customer is stuck with a 24 gallon gas tank.
Federal regs do not allow swapping out a factory gas tank for a larger aftermarket gas tank. OK with diesel but not with gas. So the larger tank needs to be installed at the factory.
Ford and Ram stick it to their customers by requiring a truck ordered with the larger gas tank to also have options packages. Ram for example charges $445 for the larger gas tank but also requires its customers to buy one of two options packages at a cost of $1,300 or $2,500. So the larger gas tank on the Ram 1500 requires spending at least an additional $1,745.