This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. Automotive Experiences 121 Automotive Experiences Vol. 5 No.2 (2022) pp. 121-136 p-ISSN: 2615-6202 e-ISSN: 2615-6636 Performance Optimization of Automotive Air-Conditioning System Operating with Al2O3-SiO2/PAG Composite Nanolubricants using Taguchi Method Nurul Nadia Mohd Zawawi 1 , Wan Hamzah Azmi 1,2 , Mohd Fairusham Ghazali 1 , Anwar Ilmar Ramadhan 3 1 Centre for Research in Advanced Fluid and Processes, Universiti Malaysia Pahang, 26300 Gambang, Kuantan, Pahang, Malaysia 2 Department of Mechanical Engineering, Universiti Malaysia Pahang, 26300 Gambang, Kuantan, Pahang, Malaysia 3 Department of Mechanical Engineering, Universitas Muhammadiyah Jakarta, 10510, Indonesia wanazmi2010@gmail.com https://doi.org/10.31603/ae.6215 Published by Automotive Laboratory of Universitas Muhammadiyah Magelang collaboration with Association of Indonesian Vocational Educators (AIVE) Abstract Article Info Submitted: 12/11/2021 Revised: 12/12/2021 Accepted: 13/12/2021 Online first: 08/03/2022 The performance of an automotive air-conditioning (AAC) system is influenced by a variety of operating conditions. This can be addressed by employing optimization techniques that can suggest the appropriate parameters for the best results. In this study, the optimum operating conditions for a composite nanolubricants-fuelled AAC system were investigate using Taguchi's design of experiment approach and analysis of variance (ANOVA). The motor speed value, initial refrigerant charge, and composite nanolubricants composition ratio were chosen as operating parameters to investigate the AAC system performance, focusing on the coefficient of performance (COP) and compressor work. Orthogonal arrays (ORs) L25 (5 6 ) was selected to determine the optimum operating parameters of the AAC system. The optimum values for speed, refrigerant mass, and composition ratio were determined to be A 4 B 1 C 5 (60:40, 900 rpm and 155 g), respectively. The motor speed was the significant factor influencing both COP and compressor performance by 78.13% and 89.29%. A confirmation test was conducted with the optimum levels of AAC system parameters to verify the efficiency of the Taguchi optimization method. The validation between the optimization results and the experimental results yielded a maximum error of 9.85%, indicating that the findings of this investigation were acceptable. Keywords: ANOVA; Automotive air-conditioning; Hybrid nanolubricants; Taguchi methods; Optimization 1. Introduction Optimization techniques are developed to evaluate the optimum parameters of system parameters to provide the best performance. Finding crucial parameters in data analysis that determine causality would greatly improve the total research output [1], [2]. Recently, researchers have been giving considerable attention to optimize system performance via software networks like Minitab and Design Expert [3]-[5]. In the recent decade, this is possible with the introduction of advanced computer hardware [6], innovative digital computer technology [7] and advanced simulation software. For this reason, rapid growth in research development of statistical models progressed to analyse and optimize the operating parameters. The investigation of AAC systems by experimental work has consumed much time and cost; therefore, the optimization approaches are reliable to optimize the system parameters towards the desired performance. The most popu-