peculiar to compression-ignition engines in which the main fuel is gaseous

Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures > peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed > simultaneously using pluralities of fuels > peculiar to compression-ignition engines in which the main fuel is gaseous

Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures (the non-fuel substances being gaseous F02D21/00) > peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed > simultaneously using pluralities of fuels (F02D19/12 takes precedence) > peculiar to compression-ignition engines in which the main fuel is gaseous