1.1 ISO 15550:2016 specifies standard reference conditions and methods of declaring the power, fuel consumption, lubricating oil consumption and test methods for internal combustion engines in commercial production using liquid or gaseous fuels. It is applicable to the following: a) reciprocating internal combustion (RIC) engines (spark-ignition or compression-ignition engines) but excluding free piston engines; b) rotary piston engines. These engines can be naturally aspirated or pressure-charged either using a mechanical pressure-charger or turbocharger. 1.2 ISO 15550:2016 is applicable to engines used for the following: a) land, rail-traction and marine use as defined in ISO 3046-1; b) the propulsion of automotive vehicles as defined in ISO 1585 and ISO 2534; c) motorcycles as defined in ISO 4106; d) the propulsion of agricultural tractors and machines e) the propulsion of earth-moving machinery as defined in ISO 9249; f) the propulsion of recreational craft or other small marine craft up to 24 m hull length as defined in ISO 8665. ISO 15550:2016 can 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. It also can be applied to tests performed both on a test bed at a manufacturer's works as well as on site.