This publication is the next part of the article “The influence of cetane-detergent additives in diesel fuel increased to 10% of RME content on energy parameters and exhaust gas composition of a diesel engine”. The cause-effect analysis of the phenomena related to the impact of 3 additive packages used in diesel oil with RME content increased to 10% (compare to standard diesel fuel with 7% of RME) was described. The basis for the analysis of the impact of the tested fuels on energy parameters and composition of exhaust gases were the parameters of indicator diagrams and heat release parameters. It was found that the first set of additives affects the delay of auto-ignition of fuel and kinetic fuel combustion speed only at low engine loads. In this range of engine operation the NOx concentration in the exhaust gas is low and besides there is a large of EGR.The second additive package was operated at high engine loads but its impact on the lower self-ignition delay was quantitatively small. Therefore, in the third packet of additives, the amount of additives used in the second packet was doubled. Then a satisfactory shortening of the self-ignition delay and reduction of the max rate of kinematic heat release was achieved as a reason of a reduction of NOx concentration in the exhaust up to 8% (compared to the reference fuel).