WLTC

WLTC stands for Worldwide Harmonized Light Vehicles Test Cycle. It is a standardized driving cycle used to measure fuel consumption, CO2 emissions, and regulated pollutant emissions from light-duty vehicles, including passenger cars and light commercial vehicles. The WLTC is part of a global harmonization effort coordinated by international and regional authorities to improve comparability of vehicle emissions data across countries and brands.

Developed within the Worldwide Harmonized Light Vehicles Test Procedure framework, the WLTC aims to better represent real-world driving conditions than older cycles. It is designed to capture a broad range of driving patterns by combining urban, suburban, and highway segments into a single test sequence, thereby producing results that reflect more dynamic acceleration, braking, and speed variation.

The cycle comprises four progressively demanding speed profiles—low, medium, high, and extra-high—that are executed on a chassis dynamometer under specified ambient conditions, including a cold-start phase. The goal is to produce standardized measurements of fuel or energy consumption and regulated emissions that can be used for vehicle type approval, labeling, and regulatory compliance.

Regulatory use of the WLTC often occurs in conjunction with the broader WLTP framework, and many jurisdictions have adopted WLTC-based procedures to replace older testing methods. While WLTC provides a more realistic baseline than its predecessors, actual real-world performance can still differ due to factors such as driving behavior and environmental conditions, which has driven the development of complementary real-driving-emissions tests in some regions.