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In a move to reduce dependence on imported fossil fuels, develop and utilize indigenous renewable and sustainably-sourced clean energy sources, the Philippines enacted the Biofuels Act of 2006 (or Republic Act 9367) that mandated blending of biodiesel with commercially sold diesel fuels which presently is at 2% coconut methyl ester (CME) by volume. Deliberations are underway to shift to 5% by volume so that data on the effects on performance and emissions of percentage blends are necessary. This study presents fuel consumption and emissions measurements of an in-use passenger van with a common-rail direct injection (CRDI) powertrain fueled with 2, 5, 10, & 20 percent CME-diesel blends by volume (designated as B2, B5, B10, & B20 respectively) driven on the Japanese 10–15 Mode drive cycle. Results indicate B2-B20 had only a marginal effect on heating values, fuel blend density, and maximum power. Relative to neat diesel, the blends showed a 1–5% lower specific fuel consumption (SFC) with B5 lowest. Mileage was 1–5% higher with the blends with B5 highest. CO decreased with increasing blend. THC emissions of B1-B20 were roughly half that of diesel. NOx from the CME blends was marginally lower than diesel. The CO and THC trends agreed with published literature and usually ascribed to overall lean mixtures and increased amount of oxygenated fuel at higher CME blends. The NOx results need further investigation as it seemed to contradict other studies. Based on these results, B5 yielded the best combination of fuel economy and emissions improvement over neat diesel and B2 without performance loss.

Due to the danger of depletion of world petroleum reserve and environmental concerns the “Philippines Biofuels Act of 2006” (Republic Act No. 9367) was established to develop and strengthen the use of local sustainable fuels, particularly the use of Coconut Methyl Ester (CME) biodiesel blends in the country. As of 2015, with respect to biodiesel in the Philippines only 2% of biodiesel is required to be blended in commercially available fuels. The National Biofuels Board of the Philippines is planning to increase the percentage of the blend within the next 5 years however only few studies are conducted to prove the effectiveness of the increase in percentage. Also in pursuant to “Philippine Clean Air Act of 2009” (Republic Act No.8749) The Department of Environmental and Natural Resources (DENR) issued an administrative order with regards to the implementation of EURO 4/IV Emission Limits within the country. This study investigates the influence of various CME Biodiesel blends in a light duty automotive CRDi engine without any engine modifications through evaluation of performance and emission characteristics, The emission characteristics will be also be investigated if it meets the EURO 4/IV emission limits set by DENR. Five fuel blends B2 (2% CME, 98% Neat Diesel), B5 (5% CME, 95% Neat Diesel), B10 (10% CME, 90% Neat Diesel), B15 (15% CME, 85% Neat Diesel) and B20 (20% CME, 80% Neat Diesel) were used and their results is compared to B0 (Neat). This will also The tests were performed at the University of the Philippines Vehicle Research and Testing Laboratory at steady state conditions, a naturally aspirated water cooled four cylinder Common Rail Direct Injection Diesel (CRDi) engine, with varying speeds from 800 to 4000 RPM at an interval of 400 RPM while maintaining the throttle 100% wide open. As a result of the investigation at typical engine speed range (1200–2400 RPM) no significant differences for biodiesel blends vs. neat diesel were observed for torque, power, CO2 and NOx emissions. However, a decrease of HC and CO was observed. Meanwhile, at 2800–4000 RPM, an increase in torque, power, CO2 and NOx, but no significant differences in HC and CO emissions. However, the engine does not normally run at the higher speed range (1800–2400 RPM) for a long period of time. With respect to biodiesel blends, torque, power, CO2, and NOx emissions generally increase with increasing biodiesel blend, while CO and HC emissions generally decreased with increasing biodiesel blend.

As part of efforts to mitigate climate change by reducing fuel consumption in the transport sector in the Philippines, this paper presents the initial results of an investigation on the effects of engine tuning on fuel economy for different drive cycles using a commercially available piggyback tuning “chip” to modify fuel rail pressure from stock settings of a CRDI diesel passenger van. The drive cycles used in this study were the Japanese 10-15 Mode, US highway fuel economy test (HWFET), and one labeled “SMN” based on a Metro Manila local route. An initial steady state vehicle fuel economy performance map at five speeds per gear position and stock tuning was obtained from chassis dynamometer tests. The same series of tests were done with the tuning chip’s settings of progressively lower rail pressure to identify the setting giving lowest fuel consumption at each gear. Fuel consumption reduction of up to 47% was observed although not all speeds at a given gear and tuning setting gave reduced values. These lowest fuel settings were applied to corresponding gear positions in each of the selected drive cycles resulting to “specific tuning maps” per drive cycle. The test vehicle was then driven with these drive cycle-specific tuning maps and the fuel economy measured. It was found that overall fuel economy decreased with drive cycle-specific tuning settings. It was then decided to try using a constant tuning setting throughout a drive cycle to see if fuel economy improved. Trials with the Japanese 10-15 Mode cycle at different constant lower rail pressure settings likewise gave overall lower fuel economy. However, a more detailed look showed that in the constant-speed portions of the cycle, fuel consumption savings of up to 35% were realized while it worsened in the accelerating and decelerating sections. The drive cycle test results indicate that the engine ECU compensated for the lowered rail pressure, maybe with increased injection duration, to increase the amount of fuel injected to meet the road-load requirements imposed by the drive cycle. Control response instabilities may have also contributed to higher fuel consumption. Engine tuning by rail pressure reduction only was most effective in reducing fuel consumption for steady state driving and ineffective for transient driving under the conditions and methodology of this study.

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