For consumers to effectively compare the environmental performance of different car models, standardized laboratory tests are essential. These tests, based on specific driving cycles, ensure reproducibility and comparability in assessing fuel consumption, CO2, and pollutant emissions. This standardized approach is crucial because only a controlled laboratory environment with a repeatable procedure allows for fair comparisons across various vehicles.
Prior to September 1, 2017, the New European Driving Cycle (NEDC) served as the primary protocol for these measurements in Europe. However, the Worldwide harmonised Light-duty vehicle Test Procedure (WLTP) has since been introduced and is gradually replacing the NEDC, aiming to provide more accurate and relevant data.
The New European Driving Cycle (NEDC)
The NEDC was the established European standard for measuring fuel consumption and emissions from passenger cars and light commercial vehicles for a significant period. Originating in 1970 with a focus on urban driving, it was expanded in 1992 to include an extra-urban phase. Since 1997, the NEDC has been the benchmark for assessing fuel consumption and CO2 emissions.
Despite its long-standing use, the NEDC’s composition became increasingly misaligned with contemporary driving habits and road usage. Characterized by a low average speed of just 34 km/h, gentle accelerations, and a maximum speed capped at 120 km/h, the NEDC cycle no longer accurately reflected real-world driving conditions.
The Worldwide harmonised Light-duty vehicle Test Procedure (WLTP)
The WLTP utilizes new Worldwide harmonised Light-duty vehicle Test Cycles (WLTC) to evaluate fuel consumption, CO2, and pollutant emissions. The core objective of the WLTP is to offer consumers more realistic data that better represents the vehicle’s performance under everyday driving scenarios.
The WLTP procedure is distinguished by a more dynamic driving profile featuring more pronounced acceleration and deceleration phases. The maximum speed is increased to 131.3 km/h, the average speed rises to 46.5 km/h, and the total cycle duration is extended to 30 minutes, a 10-minute increase compared to the NEDC. Furthermore, the distance covered in the test doubles from 11 to 23.25 kilometers.
The WLTP test comprises four distinct sections based on maximum speed: Low (up to 56.5 km/h), Medium (up to 76.6 km/h), High (up to 97.4 km/h), and Extra-high (up to 131.3 km/h). These segments are designed to simulate a range of driving environments, including urban, suburban, extra-urban roads, and motorways.
Moreover, the WLTP methodology considers all vehicle options that can influence aerodynamics, rolling resistance, and vehicle mass. This comprehensive approach results in a CO2 emission value that is more specific to the individual vehicle’s configuration.
In conclusion, the WLTP represents a significant advancement in vehicle emission testing, providing consumers with more relevant and realistic data compared to the older NEDC standard. This shift ensures a more accurate understanding of vehicle performance and environmental impact in today’s driving conditions.
