ABSTRACT Biodiesel‐fueled diesel engines offer lower emissions and improved sustainability, yet their adoption remains limited by high transesterification costs and increased NOx formation. This study examines the impact of adding water to a crude palm oil blend (DCPO) on engine performance, emissions, and wear characteristics. A Crude Palm Oil Water Emulsion Fuel (DCPOE) was produced without chemical surfactants using an in‐house Real Time Non‐Surfactant Emulsion Fuel Supply System (RTES). Engine tests showed that DCPOE delivered brake specific fuel consumption and brake thermal efficiency comparable to B10 diesel. NOx emissions decreased by 65.5%, 3.1%, and 21.6% at idling, 1 and 2 kW loads, respectively, and remained consistently lower than those of DCPO. Smoke opacity was reduced by up to 11.9%, while exhaust gas temperature and CO emissions increased slightly due to the higher oxygen and water content. Lubricating oil analysis indicated reduced iron and chromium concentrations, suggesting lower cylinder liner and piston ring wear relative to B10 diesel operation. Overall, the RTES‐generated CPO water emulsion fuel shows strong potential as a cost effective, additive free, and cleaner diesel alternative with measurable tribological benefits.
Ismail et al. (2026) studied this question.