Yogyakarta, October 2025 — The research team from the Department of Mechanical Engineering, Vocational College, Universitas Gadjah Mada (DTM SV UGM), particularly from the Heavy Equipment Maintenance and Management Engineering Study Program (TPPAB), has successfully completed a study focusing on the performance and fuel efficiency analysis of the Komatsu PC195LC diesel engine, with specific emphasis on the fuel injection system and injector components.
This research represents a continuation of a long-term collaborative initiative between academia and industry, aimed at the development of environmentally friendly and fuel-efficient excavator units. The research involved both academic and industry experts, including Yosephus Ardean Kurnianto Prayitno, Sugiyanto, Ilham Ayu Putri Pratiwi, Braam Delfian Prihandianto, Muhammad Novan Budi Prasetyo, Sutikno, Josua Aditya Manuel, Haidar Ali Fikri, Yanuar Khafid H., and Setyawan Adi Nugroho. The study was conducted from July 1 to October 17, 2025, in collaboration with PT United Tractors Tbk Semarang Branch and UT School Semarang.
The project began with technical coordination between DTM SV UGM and PT United Tractors to define the research scope, testing parameters, and implementation stages. After an extensive review of literature related to high-pressure diesel fuel injection systems, the study advanced into data collection on engine performance and fuel efficiency, conducted during a Public Training session at UT School Semarang.
The research approach integrated both field testing and laboratory simulation, allowing the team to observe key performance indicators such as combustion characteristics, fuel consumption, and injector spray behavior (spray pattern and droplet distribution). This combination of empirical and simulated analysis enabled a comprehensive understanding of the relationship between injection parameters and engine efficiency.
Field results revealed that the original Komatsu (OEM) injector achieved up to 3.45% higher fuel efficiency at high engine speeds compared to the local Bosch injector. Furthermore, the OEM injector demonstrated greater durability and performance stability after 3,000 operating hours, maintaining performance levels close to new-condition standards.
In terms of exhaust emissions, both injector types complied with Euro 4 emission standards, showing low levels of COand NOx. However, a relatively high oxygen concentration (O₂ >15%) was detected, indicating a potential air–fuel ratio imbalance, possibly due to sensor calibration drift or intake manifold irregularities that may require further maintenance.
These findings highlight the critical role of injector quality and condition in determining combustion efficiency, fuel economy, and emission stability in high-pressure diesel engines. The injector’s precision not only affects energy utilization but also directly influences the machine’s long-term reliability and environmental footprint.
Through a combination of experimental testing and simplified modeling of fuel spray characteristics, this research successfully demonstrated the interconnection between injection pressure, injector condition, and combustion efficiency. The results provide a practical reference for the heavy equipment industry, especially in implementing predictive maintenance strategies and optimizing the operational performance of Komatsu PC195LC diesel engineswidely used in construction and mining sectors.
Beyond its technical contributions, this research reinforces the role of DTM SV UGM as a vital bridge between academia and industry, driving applied studies that promote energy efficiency, system reliability, and sustainable operations. The collaboration exemplifies how academic research can deliver tangible industrial impact, directly contributing to improved performance, lower emissions, and greener operational practices.
This collaborative research also aligns with several United Nations Sustainable Development Goals (SDGs), including:
• SDG 7 – Affordable and Clean Energy, through enhanced combustion efficiency and reduced fossil fuel consumption;
• SDG 9 – Industry, Innovation, and Infrastructure, by fostering synergy between academia and industry in developing more efficient heavy machinery technologies;
• SDG 13 – Climate Action, by contributing to emission reduction and the transition toward cleaner and more sustainable industrial operations.
Contributors:
Department of Mechanical Engineering, Vocational College, Universitas Gadjah Mada
Industry Partners: PT United Tractors Tbk Semarang Branch and UT School Semarang, represented by Muhammad Novan Budi Prasetyo, Sutikno, Josua Aditya Manuel, Haidar Ali Fikri, and Yanuar Khafid H.
Researchers: Yosephus Ardean Kurnianto Prayitno, Sugiyanto, Ilham Ayu Putri Pratiwi, Braam Delfian Prihandianto, Setyawan Adi Nugroho, and Tofaenal Akhyar