<![CDATA[Abstract This study compares Pertalite, Pertamax, and Pertamax Turbo on engine performance, fuel consumption, and exhaust emissions of a 2005 Honda Karisma equipped with a KPH-series engine. An experimental method was used at the Automotive Main Workshop, Universitas Negeri Yogyakarta. The motorcycle remained in standard condition and was tuned before testing. Each fuel was tested three times under the same procedure. Engine torque and power were measured using a Dynojet 250i chassis dynamometer, fuel consumption was determined volumetrically over a 100m dynamometer test, and exhaust emissions were measured at idle using a gas analyzer. The results showed only small differences among the fuels. Pertamax Turbo produced the highest average torque,8.01N·m, and the highest average power,5.91hp. Pertalite produced the lowest average fuel consumption, corresponding to 40.00km/L, compared with 37.97km/L for Pertamax and 36.14km/L for Pertamax Turbo. The measured CO concentrations were 6.68%,7.10%, and 6.57%, while HC concentrations were 2,919,3,079, and 2,814 ppm for Pertalite, Pertamax, and Pertamax Turbo, respectively. These findings indicate that, on the standard KPH engine used in this study, increasing fuel octane rating did not produce a large improvement in power or torque, whereas Pertalite provided the best measured fuel economy and Pertamax Turbo produced the lowest CO and HC values among the three tested fuels. Abstrak Penelitian ini membandingkan penggunaan Pertalite, Pertamax, dan Pertamax Turbo terhadap performa mesin, konsumsi bahan bakar, serta emisi gas buang Honda Karisma tahun 2005 dengan seri mesin KPH. Penelitian menggunakan metode eksperimen di Bengkel Induk Otomotif Universitas Negeri Yogyakarta. Sepeda motor dipertahankan dalam kondisi standar dan dilakukan tune-up sebelum pengujian. Setiap jenis bahan bakar diuji sebanyak tiga kali dengan prosedur yang sama. Torsi dan daya diukur menggunakan chassis dynamometer Dynojet 250i, konsumsi bahan bakar diukur secara volumetrik pada pengujian sejauh 100 m di atas dynamometer, sedangkan emisi gas buang diukur pada kondisi idle menggunakan gas analyzer. Hasil pengujian menunjukkan perbedaan yang relatif kecil antarjenis bahan bakar. Pertamax Turbo menghasilkan torsi rata-rata tertinggi sebesar 8,01 N·m dan daya rata-rata tertinggi sebesar 5,91 HP. Pertalite menghasilkan konsumsi bahan bakar paling hemat, yaitu 40,00 km/L, dibandingkan Pertamax 37,97 km/L dan Pertamax Turbo 36,14 km/L. Kadar CO yang terukur berturut-turut sebesar 6,68%, 7,10%, dan 6,57%, sedangkan kadar HC sebesar 2.919, 3.079, dan 2.814 ppm untuk Pertalite, Pertamax, dan Pertamax Turbo. Temuan ini menunjukkan bahwa pada mesin KPH standar dalam penelitian ini, peningkatan nilai oktan tidak menghasilkan peningkatan besar pada daya dan torsi; Pertalite memberikan efisiensi bahan bakar terbaik, sedangkan Pertamax Turbo menghasilkan kadar CO dan HC terendah di antara ketiga bahan bakar yang diuji.]]>
