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Several new combustion concepts have been developed during last decade with the aim of reducing pollutant emissions. Specifically, these strategies allow a simultaneous reduction of NOx and soot emissions by reducing the local combustion temperatures, enhancing the fuel/air mixing (PCCI, HCCI…). In spite of their benefits, these concepts present difficulties controlling the appropriate combustion phasing as well as high knocking levels and therefore, their operating range is reduced to low-medium loads. In this work gasoline is considered as a fuel in order to improve combustion strategies based on fully or partially premixed combustion in CI engines. Its use provides more flexibility to achieve lean and low combustion temperature, however the concept has demonstrated difficulty under light load conditions using gasoline with ON up to 95.

Regulations on emissions from diesel engines are becoming more stringent worldwide. Hence there is a great deal of interest in developing engine combustion systems that offer the fuel efficiency of a diesel engine, but with low smoke and NOx emissions. Thus, premixed compression ignition combustion is an interesting way to achieve a clean and efficient engine. However, using a high reactivity fuel such as diesel fuel leads to a complex and expensive engine design. A proven way to overcome this drawback is to actively control the reactivity of the fuel using low cetane fuels such as gasoline. This strategy has been explored with single and multiple cylinder engines. However no detailed and well conducted studies of the injection process were found related to the effects of gasoline use in a standard commercial compression ignition diesel engine injection system.