This research focused on evaluating the technical viability of using biodiesel with a blending ratio of 40% v/v, which is expected to be implemented soon in Indonesia. Two kinds of biodiesel blends were prepared, a blend of 60% diesel fuel and 40% biodiesel (B40) and a blend of 60% diesel fuel, 30% biodiesel, and 10% hydrogenated vegetable oil (HVO) (B30D10). The fuels were tested on EuroII vehicles without any engine modifications through a 50,000 km endurance road test. Laboratory tests were also performed at certain traveled distances to evaluate various engine parameters, including power, fuel economy, exhaust emissions, and used engine oil properties. Engine components were inspected upon the completion of the road test. Cold-start ability was also examined to confirm the suitability of the investigated biofuels at low-temperature operating conditions in Indonesia. The road test results showed that vehicles fuelled with B40 and B30D10 could reach a distance of 50,000 km without encountering any technical issues. The laboratory evaluation during the road test indicated that B30D10 had a higher power and fuel economy than B40, with a maximum difference of 2%. Furthermore, B30D10 emitted lower CO, HC, and PM emissions than B40 throughout the distance traveled, with maximum differences of 11.4%, 14.7%, and 22.6%, respectively, but led to 15% higher NOx. Engine component inspection and used engine oil analysis confirmed the fulfillment of the manufacturer's recommendations for both B40 and B30D10. Finally, B40 and B30D10 were suitable for operating at low ambient temperatures in Indonesia, confirming them as practical options to be implemented in the nationwide 40% biodiesel blend fuel.

In this study, biodiesel fuel with a ratio of 20% volume (B20) was used on vehicles that are used in common rail injection systems, complying with Euro2 emission regulations. Laboratory and road tests were conducted to evaluate the effects of B20 on performance, emissions and engine components. Using diesel fuel and B20 as reference fuels, tests were conducted using Euro2 vehicle technology to investigate the effects on emissions, fuel consumption, and power. Durability testing was run for travel distances covering 40,000 km under various road and environmental conditions, while vehicle performance and emissions tests were conducted using the ECE R84-03 and ECE R101 test methods, respectively. The results show that B20 has lower CO and hydrocarbon (HC) emissions for every distance travelled, with an average of around 30%. Particulate emission was a bit lower, averaging 3.4% for B20 compared to B0, while NOx was found to slightly increase at around 2% for B20. Due to its lower calorific value, for an average distance traveled, the fuel economy of B20 was around 0.5% higher compared to B0. Furthermore, the maximum power of B20 was 3% lower compared to that of B0 for the entire distance traveled. However, an evaluation of engine components after 40,000 km showed that B20 and B0 were similar. Moreover, vehicles using B20 tend to have a comparable durability of engine components when compared with B0.

The smoke point of several fuel mixtures was measured using a smoke meter defined by American Society for Testing Material D1322. The threshold soot index (TSI) was calculated to compare the sooting tendency of fuels. Two aviation biofuels produced by hydroprocessing of coconut oil, four jet range normal paraffins (n-paraffins), iso-octane, and propylbenzene were used to investigate the effects of chain length of n-paraffins, iso-paraffins, and aromatics on the sooting tendency. The results show that the effect of propylbenzene on the smoke point of the mixtures is dominant compared to that of the chain length of n-paraffins and the fraction of iso-paraffins. The differences in the sooting tendency among these n-paraffins are insignificant. In addition, blending aviation biofuels with Jet A1 leads to a decrease in the sooting tendency. Aromatics in Jet A1 play an important role on the sooting tendency of the mixtures of aviation biofuels and Jet A1.