Payload is the maximum permissible weight of the transported load — i.e., total weight minus the empty weight of the machine. For articulated dump trucks and dumpers, payload is the central performance metric: a Volvo A30G has 28 tonnes payload, a Cat 797F Mining Truck 363 tonnes.
Economical payload utilization is decisive for transport costs per tonne. Overloading damages the drivetrain, frame, and tires and is illegal on public roads. Underloading wastes fuel and machine time. Onboard weighing systems (payload meters) measure the load in real time and display the fill level to the operator.
For wheel loaders, payload is specified as loose material payload (loose material in the bucket, density-dependent) and as lifting capacity (total load over bucket edge at full lift height). Tipping payload (at which the rear axle just lifts off) is the theoretical maximum value — the permitted operating load is 50 % of tipping payload.