This International Standard specifies how to make a declaration of the engine weight (mass) for internal combustion engines. For the purposes of this International Standard, the word weight is used as the direct equivalent of the word mass. This International Standard applies to reciprocating internal combustion engines (spark-ignition or compression ignition engines) but excluding free piston engines, and rotary piston engines. These engines may be naturally aspirated or pressure-charged, either by a mechanical pressure-charger or a turbo-charger. This International Standard applies to engines for the following: land, rail-traction and marine use; the propulsion of automotive vehicles; propelling (or powering) non-road mobile machinery; motorcycles; the propulsion of agricultural tractors and machines; the propulsion of earth-moving machinery as defined in ISO6165; the propulsion of recreational or other small marine craft of hull length up to 24m. This International Standard may be applied to engines used to propel road-construction machines, industrial trucks and for other applications where no suitable International Standard for these engines exists.