Fuel lubricity is an essential property that ensures the longevity end efficiency of diesel CI engines. Nanomaterials have been shown to have the potential to improve lubricity in many different lubricating substances, including fuels. Moreover, the combustion process has also been shown to improve with the introduction of nanomaterials. This study investigated a series of nanoparticles, including carbon nanoplates, carbon nanotubes, aluminum oxide, zinc oxide, and cerium oxide, as lubricity-enhancing additives for selected fuels. Conventional diesel fuel and rapeseed oil methyl ester, referred to as biodiesel, were chosen as base fuels for modification. The lubricity was evaluated according to the standard test method ASTM 6079 using the HFRR tribometer. The leading lubricity indicators were the wear scar diameter, wear volume, and coefficient of friction. In addition, the worn surface analysis was performed to elucidate the lubrication mechanism. The results show that the addition of nanoparticles can improve the lubricity of both investigated fuels. However, the effect differed among nanoparticles and fuels. In summary, carbon nanotubes could be a rational choice for both fuels. In addition, zinc oxide improved the lubricity of diesel fuel, while carbon nanoplatelets and aluminum oxide nanoparticles showed improvements in the lubricity of biodiesel.

This article presents the test results of a turbocharged Common Rail Direct Injection (CRDI) diesel engine operating on diesel fuel and methyl ester biodiesel with nanoparticle additives. The use of nanomaterials has been shown to improve the combustion process. In this study, various nanoparticles, including zinc oxide and carbon plates, were investigated as additives to enhance the combustion performance of selected fuels. The fuel of choice was conventional diesel, and a methyl ester of rapeseed oil called biodiesel. A turbocharged Common Rail Direct Injection (CRDI) diesel engine, model FIAT 192A1000, was used for the experiments. The following engine parameters were measured and recorded: torque (Ms, Nm), fuel consumption (Bd, kg/h), carbon monoxide (CO, ppm), and nitrogen oxides (NO_x, ppm). The results show that nanoparticles can improve the combustion performance of the fuels studied in the engine. However, the effect of nanoparticles on engine parameters varied. In summary, the influence of nanoparticles is noticeable: the ID is shorter with diesel fuel with carbon nanotubes at 50 ppm and 100 ppm concentration, the NO_x is reduced with zinc oxide and D, and CO is diminished in all load modes when using RME with carbon nanotubes.

Heavy-duty transit vehicles (N1–N3) (heavy vehicles) can generate disproportionate environmental and economic impacts in urban transport corridors despite representing a relatively small share of total traffic volume. This study develops an integrated probabilistic framework for assessing the relationships between traffic-flow variability, CO₂e emissions, particulate-matter-derived climate impacts, and external pollution costs associated with transit transport. The methodology combines traffic-flow modeling, emission estimation, PM-to-CO₂e transformation, probabilistic analysis, Monte Carlo simulation, sensitivity analysis, and scenario-based intervention assessment. Separate analyses were conducted for M1 passenger vehicles and heavy vehicles to evaluate differences in emission behavior, uncertainty, and economic impacts. The results indicate substantial structural differences between light-duty and heavy-vehicle regimes. Passenger-car traffic exhibited relatively stable emission distributions, whereas heavy vehicles demonstrated significantly greater variability, uncertainty, and emission intensity. Sensitivity analysis identified heavy-vehicle flow as the dominant factor influencing overall system emissions and pollution costs. Scenario analysis indicated that restrictions targeting heavy-vehicle traffic have the potential to generate considerably larger environmental benefits than generalized traffic-reduction measures. Probabilistic assessment further revealed that heavy vehicles contribute disproportionately to high-emission risk regimes and uncertainty propagation within the system. The proposed framework provides an integrated approach for evaluating climate impacts, uncertainty and economic externalities of transit transport. The results highlight the importance of heavy-vehicle management in reducing emissions and pollution costs while supporting risk-informed transport policy development.

This article presents an analysis of regular diesel fuel and synthetic diesel fuel—hydrogenated vegetable oil (HVO)—evaluating their economic and environmental performance under real-world operating conditions. Experimental tests were conducted on a BMW E46 330D, measuring fuel consumption, engine power, torque, CO₂ emissions, and other exhaust gases while driving in city and suburban modes. The results show that average fuel consumption increased by approximately 10% when using HVO compared to regular diesel. The decrease in engine performance was minimal: power decreased by about 1.93%, and torque by 0.85%. From an environmental perspective, HVO significantly reduced CO₂ emissions and smoke opacity (by up to 37.5%), as well as CO and Hydrocarbon emissions. However, a slight increase in NOₓ emissions was observed under certain load conditions. HVO is an alternative to regular diesel fuel that ensures better environmental performance with only minor economic and operational compromises.