Reduction of the NOx emissions in vehicle diesel engine in order to fulfill future rules concerning emissions released into air.

In the past period occurred information about a fact that in some of the motorcars was installed a software, which enabled to hide the over-limit values of the nitrogen oxides during the emission testing process. This affair is called "dieselgate". It is a well-known fact that the actual emission limits are very hard and there is arising a serious problem for automobile factories to meet the demanding emission requirements. The emission standard Euro is an obligatory standard, which is valid within the European Union. On the present there is valid the newest standard Euro 6, which should help to eliminate most of the undesirable substances that are influencing quality of air. However, already in this year or during the next year 2018 there will be implemented a new, stricter emission standard Euro 7 in the EU. From this reason started to be used some of the alternative fuels in this branch. There was performed a study, which investigated emissions of the vehicle diesel engine during application of the experimental fuels. The experimental engine was equipped with the turbocharging and with the direct fuel injection. The different testing fuels were created using the ratios 0%, 50%, 80% and 100% between the biodiesel and the ULSDF (Ultra Low Sulphur Diesel Fuel), whereas the individually mixed fuels were marked B0:U100, B50:U50, B80:U20 and B100:U0. The first kind of the applied fuel is the pure ULSDF and the last fuel is the pure biodiesel. The experimental measurements were performed at the different engine loading levels and various engine speeds in order to investigate an influence of the mixed fuels on the engine operational characteristics.