The maximum safe weight a tire can carry at a specified pressure. This rating is stated on the side of each tire. Suspension systems have a manufacturer's weight capacity rating. Coupling Device Capacity. Legal Weight Limits You must keep weights within legal limits.
States have maximums for GVWs, GCWs and axle weights.
Often, maximum axle weights are set by a bridge formula. A bridge formula permits less maximum axle weight for axles that are closer together. This is to prevent overloading bridges and roadways. Overloading can have bad effects on steering, braking, and speed control. Overloaded trucks have to go very slow on upgrades.