## 1 Introduction  
The global automotive diesel engine market by region includes North America, Asia-Pacific, Europe, South America, and the Middle East and Africa [1]. The Asia-Pacific region shows clear dominance, accounting for the largest market share (45%), due to its rapid industrialization and infrastructure development, which require reliable energy sources and the use of heavy equipment [2]. According to a global report, the global automotive diesel engine market is expected to grow in average of approximately 4% between 2023 and 2028, with Asia-Pacific being the fastest growing region, followed by North America and Europe [3]. Active economic and scientific development of the Arctic and northern territories has led to a sharp increase in the demand of diesel fuel with improved low-temperature properties [4]. Low temperature properties determine the ability of fuel to flow smoothly into the engine from the fuel tank. At low temperatures, the mobility of the fuel decreases, which leads to deterioration in pumpability through pipelines and filters due to the crystallization of n-paraffin hydrocarbons contained in its composition. Low-temperature properties include three indicators: cloud point, cold filter plugging point and pour point. The cloud point (CP) characterizes a change in the phase composition of the fuel, namely the formation of not only the liquid phase of the fuel, but also the solid one. Cloudiness manifests itself as a change in the appearance of the fuel from clear to cloudy. As the temperature decreases, the crystallization of n-paraffins that are present in the fuel begins, but at this stage, the crystals are still small in size, which still allows the fuel to be pumped through the filters, forming only a thin film of n-paraffins on them. With a further decrease in temperature, the amount of solid phase increases, which is explained by the growth and association of n-paraffin crystals, and also the formation of framework structures. The fluidity of the fuel decreases, which prevents it from further passing through the fuel filters. The temperature at which fuel stops passing through the filters is called the cold filter plugging point (CFPP). With an even greater decrease in temperature, the fuel finally loses its mobility, the frame structures become more and more branched, the length of n-paraffin chains increases, and the fuel solidifies. The temperature at which this phenomenon occurs is called the pour point (PP). Diesel fuel has different requirements in different regions of the world. According to the standard [5], in conformity the requirements for CFPP, diesel fuels for temperate climates are divided into 6 grades. Each of the varieties has its own temperature, so for grade A CFPP should not exceed 5 \({}^{\circ}\)C, for grade B 0 \({}^{\circ}\)C, for grade C \(-\)5 \({}^{\circ}\)C, for grade D \(-\)10 \({}^{\circ}\)C, for grade E \(-\)15 \({}^{\circ}\)C, for grade A \(-\)20 \({}^{\circ}\)C. According to the CFPP requirements, diesel fuels for cold and arctic climates are divided into 5 classes. So, for class 0, the CP should be no more than \(-\)10 \({}^{\circ}\)C, the CFPP should not be more than \(-\)20 \({}^{\circ}\)C; for class 1: \(-\)16 \({}^{\circ}\)C and \(-\)26 \({}^{\circ}\)C; for class 2: \(-\)22 \({}^{\circ}\)C and \(-\)32 \({}^{\circ}\)C; for class 3: \(-\)28 \({}^{\circ}\)C and \(-\)38 \({}^{\circ}\)C, for class 4: \(-\)34 \({}^{\circ}\)C and \(-\)44 \({}^{\circ}\)C, respectively. On the territory of the Russian Federation, the requirements for the CFPP of diesel fuels are determined according to [6]. Thus, the CFPP for a summer grade of diesel fuel should not exceed \(-\)5 \({}^{\circ}\)C, for an inter-season grade \(-\)15 \({}^{\circ}\)C, for a winter grade \(-\)25 \({}^{\circ}\)C; for the Arctic \(-\)45 \({}^{\circ}\)C.  
To production, diesel fuel with improved low-temperature properties, processes that improve the PP and CFPP are introduced into its production technology.