Online Training & Materials World Harmonized Transient Cycle (WHTC) Share SHARE Facebook share Twitter LinkedIn Copy URL Email Download Download whtc.php en Added on: 02 March, 2026 Breadcrumb Home Resource Library World Harmonized Transient Cycle (WHTC) Dieselnet’s WHTC page describes the World Harmonized Transient Cycle, a transient engine dynamometer test cycle used for heavy-duty engine emissions measurement and certification.It can support teams working on heavy-duty standards and testing capacity by clarifying how transient cycles represent real-world operating conditions in laboratory certification.