Universitas Negeri Yogyakarta (UNY) conducted emissions testing for private and official vehicles at the Rectorate courtyard on Tuesday (May 26, 2026). According to the Head of Infrastructure, Facilities, and Household Affairs of UNY, Indun Probo Utami, M.Pd., the purpose of this emissions test was to comply with the requirements of Government Regulation No. 22 of 2021 concerning the Implementation of Environmental Protection and Management. “In addition, this initiative also helps maintain air quality in Yogyakarta while increasing public awareness of the importance of motor vehicle emissions testing,” said Indun. The emissions test targeted more than 30 diesel and gasoline-powered vehicles, including four UNY-owned buses, to examine their emission levels.

The emissions testing utilized equipment from the Automotive Engineering Laboratory, Faculty of Engineering, UNY. According to Idham Ahmad Shohibul, a student from the Automotive Engineering Education Program at the Faculty of Engineering who participated in the testing, vehicles pass the emissions test if the exhaust emission results comply with the emission standards established by the government. “The emission threshold for motor vehicle exhaust gases is regulated under Government Regulation No. 22 of 2021 concerning the Implementation of Environmental Protection and Management,” he explained.

Gasoline-powered motor vehicles (spark ignition engines) are considered to pass the emissions test if their exhaust gas emissions remain below the prescribed limits according to the vehicle’s year of manufacture. For Category M (passenger vehicles), vehicles manufactured before 2007 must have a maximum carbon monoxide (CO) level of 4% and hydrocarbon (HC) level of 1,000 ppm. Vehicles manufactured between 2007 and 2018 are limited to a maximum CO level of 1% and HC level of 150 ppm, while vehicles manufactured after 2018 must meet stricter standards, with a maximum CO level of 0.5% and HC level of 100 ppm. For Category N and O vehicles (freight and goods transport vehicles) powered by gasoline, the thresholds are CO 4% and HC 1,100 ppm (before 2007), CO 1% and HC 200 ppm (2007–2018), and CO 0.5% and HC 150 ppm (after 2018). Testing is conducted while the engine is in idle condition.

Diesel-powered vehicles (compression ignition engines) are declared to pass emissions testing based on smoke opacity values during free acceleration. For vehicles with a gross vehicle weight (GVW) of ≤ 3.5 tons, the maximum opacity limit is 65% HSU for vehicles manufactured before 2010, 40% HSU for vehicles manufactured between 2010 and 2021, and 30% HSU for vehicles manufactured after 2021. Meanwhile, diesel vehicles with a GVW > 3.5 tons have opacity limits of 65% HSU (before 2010), 40% HSU (2010–2021), and 35% HSU (after 2021). Vehicles are considered to pass if measurement results do not exceed these opacity thresholds.

According to Eko Siswanto, a laboratory technician at the Automotive Engineering Department of the Faculty of Engineering, several factors may cause vehicles to fail emissions testing, including the use of unsuitable fuel, malfunctions in the combustion system, or defects in the exhaust system. “To ensure vehicles pass emissions testing, owners should perform regular maintenance, including periodic oil and filter replacement,” he stated.

Vehicles that pass the emissions test are given a sticker placed on the rear window as proof of compliance.

The implementation of this emissions testing demonstrates UNY’s commitment to supporting a healthy and sustainable campus environment. Efforts to control vehicle emissions are aligned with the Sustainable Development Goals (SDGs), particularly SDG 3 (Good Health and Well-being), SDG 11 (Sustainable Cities and Communities), and SDG 13 (Climate Action) through the reduction of air pollution and increased public awareness of environmentally friendly vehicles.