In order to investigate the impact of four types of consumed fuels on the emission of exhaust gases from two common car engines (TU5 and XU7JP/L3) under identical conditions, an experimental study was conducted in Islam Abad Gharb, the central location for automotive technical. The study followed Factorial Completely Randomized Design with six replicates. The fuels examined in this research comprised export gasoline, super gasoline, regular gasoline, and CNG gas. The exhaust gases resulting from engine combustion, including oxygen (O2), carbon monoxide (CO), carbon dioxide (CO2), hydrocarbons (HC), and nitrogen oxides (NOX), were evaluated against international standards and those set by automotive technical inspection centers. The findings reveal notable differences in exhaust gas emissions between the XU7JP/L3 and TU5 engines when using various fuels. The volumetric percentages of oxygen produced during the combustion of export gasoline are 0.14% and 0.04% for XU7JP/L3 and TU5 engines, respectively. Additionally, carbon monoxide percentages are 0.016% and 0.023% for XU7JP/L3 and TU5 engines. Furthermore, carbon dioxide emissions are 8.56% and 10.20% for XU7JP/L3 and TU5 engines, respectively. The TU5 engine exhibits a lower impact on hydrocarbon emissions across all fuels. In terms of nitrogen oxide (NOx) concentrations, the TU5 engine consistently plays a lesser role compared to the XU7JP/L3 engine for all tested fuels. The outcomes of this study demonstrate that the TU5 engine emits fewer greenhouse gases and environmental pollutants compared to the XU7JP/L3 engine under various fuel consumption conditions.
