WLTP

WLTP stands for Worldwide Harmonised Light-Duty Vehicles Test Procedure. It is a global standard for measuring the fuel consumption, carbon dioxide (CO2) emissions, and regulated pollutant emissions of light-duty vehicles, including passenger cars and light commercial vehicles. The WLTP was developed to replace the older NEDC cycle with a test that better reflects real-world driving conditions, and it is used for official vehicle labeling and regulatory compliance in many regions.

The WLTP test procedure centers on the WLTC driving cycle, which simulates typical urban, suburban, and highway driving with higher average speeds and more representative accelerations and decelerations than the previous cycle. The test is conducted on a chassis dynamometer under standardized conditions, and it accounts for a range of preconditioning and test conditions, such as ambient temperature and auxiliary loads from equipment like air conditioning. Vehicle configurations and optional equipment can influence the results, so the procedure provides rules for how these factors should be included in the measurement.

Results from WLTP include fuel consumption, CO2 emissions, and regulated pollutant emissions such as NOx and particulate matter. These figures are used for vehicle energy labeling, fleet-wide emissions targets, and official compliance. WLTP values are typically higher than those produced under the older NEDC, reflecting more realistic operating conditions. In many regions, WLTP testing is complemented by Real Driving Emissions (RDE) measurements taken on the road to capture in-use emissions under actual driving.