Abstract: A process for the addition of ferrocene to combustion or motor fuels involves an improved metering of the additive ferrocene into the combustion chamber of an internal combustion engine or a combustion system. The process utilizes the sublimation properties of ferrocene in that ferrocene is passed through sublimation into a stream of combustion gas or a substream thereof and with the combustion or motor fuel, which is present as a vapor or finely distributed as solid or liquid particles, fed to a chemical conversion through combustion. A preferred application consists of loading the combustion chamber of a diesel engine equipped with a diesel particulate filter with a carrier gas stream enriched with ferrocene vapor in a sublimator.

Abstract: A method for reducing the consumption of fuel and emission of toxic exhaust gas and reducing engine wear of an Otto engine, equipped with an exhaust gas catalyst system for secondary combustion of exhaust gas, in which a liquid non-leaded fuel containing 1 to 100 ppm by weight of ferrocene is used.

Abstract: To avoid an unacceptably high exhaust gas back pressure when operating diesel engines equipped with a particle filter in the exhaust gas stream, an engine lubricating oil is used that has a catalytically active content of an iron compound in an amount of 5 to 20,000 ppm. The use of the additive facilitates the regeneration of the diesel particle filters by burning, especially under operating conditions of the diesel engine that lead only to relatively low exhaust gas temperatures. Iron compounds proposed are ferrocene, ferrocene derivatives, and iron salts of organic acids.