The CLTC was first adopted into regulation by the Chinese Ministry of Industry and Information Technology (MIIT) in October 2021 under the national standard "GB/T 38146.1-2019, China Automotive Test Cycle Part 1: Light Vehicles".
The CLTC testing accounts for the country's higher congestion levels with more frequent stop-and-go and lower speed limits, which lead to increased low-speed driving and longer idling times that benefits electric vehicles.
[2] In 2009, the Worldwide Harmonized Light-Duty Driving Test Cycle (WLTC) was introduced in 2009 by the Working Party on Pollution and Energy Transport Program (GRPE) under the United Nations Economic Commission for Europe (UNECE).
Chinese cities generally experience higher congestion levels, leading to a greater proportion of low-speed driving, frequent stops and longer idling times.
The CLTC testing involves three driving phases: slow, medium, and fast, with a total duration of 30 minutes and a vehicle mileage of 14.48 km (9.00 mi) on a dynamometer.
Compared to the WLTP adopted in Europe, the CLTC involves more frequent stops, accelerations, decelerations, and simulates urban traffic congestion with a lower speed limit of 114 km/h (71 mph).
[9] The following table presents a comparison of test results conducted by the Tianjin Automotive Research Institute of a sampled electric vehicle prior to the introduction of the CLTC.
[8] The CLTC has also faced criticism internationally for being perceived as "less stringent", "generous", or "unrealistic" compared to the WLTP and EPA standards when measuring electric vehicle range.
Critics argue that the CLTC may overestimate vehicle range compared to these other testing protocols, which are widely regarded as more rigorous in assessing real-world driving conditions.