Semnan University Press Journal of Heat and Mass Transfer Research 2345-508X 13 3 2026 09 01 Influence Examine of Visnaga Oil Biodiesel on the Performance and Emission Characteristics of CI Engines 285 293 9825 10.22075/jhmtr.2025.37420.1721 EN Abdulrahman Shakir Mahmood College of Mechanical Engineering, University of Technology-Iraq, Baghdad, Iraq Mohammed Kadhim Allawi Department of Mechanical Power Engineering, Baghdad-Technical Engineering College, Middle Technical University, Baghdad, Iraq Ghanim Mohammed Hachim Kerbala University, College of Engineering, Mechanical Engineering Department, Baghdad, Iraq Fouad Alwan Saleh Mustansiriyah University, College of Engineering, Mechanical Engineering Department, Baghdad, Iraq Journal Article 2025 04 16 The main reason for global warming and respiratory problems in humans is the influence of emissions from fossil fuel combustion. Levels of these pollutants have increased significantly due to the expansion of vehicle numbers, especially in Iraq, exacerbating the environmental and health impacts. Procedures to mitigate these emissions include modifying engine-part design or utilizing environmentally friendly fuel sources. The aim of this research is to perform an experimental investigation examining the use of a new type of visnaga oil biodiesel on the performance and emissions of a single-cylinder, air cooled, and 4 strokes CI engines. The visnaga oil biodiesel was added to diesel fuel in volumetric ratios of 10%, 20%, 30%, and 40%. The results of the tests show that this type of biodiesel lowers the engine's thermal efficiency while raising the EGT and BSFC. The highest decrease in BTE was 7.63% and the highest increase in BSFC was 15.28%, for biodiesel at 40% in the blend (BF40). Additionally, for the visnaga oil biodiesel, the emissions of carbon monoxide (CO) and unburned hydrocarbons (HC) were decreased, but the emissions of nitrogen oxides (NOx) and carbon dioxide (CO₂) were increased. The greatest reduction in CO and HC emissions was achieved with the use of the BF40 blend, where reductions of 24.7% and 39.5% were recorded respectively, while the NOX and CO₂ emissions increased by 36% and 38.2%, respectively. https://jhmtr.semnan.ac.ir/article_9825_f37d7df68d057dc36e068d67dccd4e82.pdf