Fuel i.e. diesel, classifying method for internal-combustion engine, involves determining frequency component, and assigning fuel in one fuel class based on characteristic that is phase assigned to component

摘要

The method involves determining a complex ignition frequency component of revolution speed spectrum of an internal-combustion engine (100) including a combustion chamber (26) in which fuel is injected by a fuel injector (18), where the component depends on combustion moment. A characteristic correlating with fuel quality characteristic is determined using the component. Fuel i.e. diesel, is assigned in one of the two different fuel classes based on the characteristic that is a phase assigned to the component, which correlates with a middle combustion position of the engine. An independent claim is also included for a computer program for fuel classification for an internal-combustion engine with a combustion chamber.