Understanding how vehicles are tested for fuel consumption and emissions is crucial in today’s automotive landscape. Standardized laboratory tests are essential for providing reproducible and comparable results across different car models, allowing consumers to make informed decisions. For years, the New European Driving Cycle (NEDC) served as the benchmark in Europe, but the automotive industry has transitioned to the Worldwide harmonised Light-duty vehicle Test Procedure (WLTP) to better reflect real-world driving conditions.
The NEDC, introduced in stages from 1970, aimed to measure fuel consumption and emissions from passenger cars and light commercial vehicles. Initially focused on urban driving, it later incorporated an extra-urban phase. However, the NEDC cycle became outdated due to its low average speed of just 34 km/h, gentle accelerations, and a maximum speed of only 120 km/h. These parameters no longer accurately represented contemporary driving styles and the variety of roads vehicles typically encounter.
In contrast, the WLTP procedure, which came into force in Europe starting September 1, 2017, utilizes new Worldwide harmonised Light-duty vehicle Test Cycles (WLTC). The core objective of WLTP is to deliver more realistic data to consumers, data that more closely mirrors everyday vehicle usage. The WLTP is characterized by a more dynamic driving profile featuring more significant 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 test duration is extended to 30 minutes. The distance covered during the test doubles to 23.25 kilometers compared to the NEDC.
The WLTP test comprises four parts categorized by speed: Low, Medium, High, and Extra-high. These segments are designed to simulate urban, suburban, extra-urban roads, and motorway driving scenarios. Furthermore, WLTP takes into account vehicle-specific optional equipment that affects aerodynamics, rolling resistance, and overall vehicle mass. This comprehensive approach results in a CO2 emission value that accurately reflects the individual vehicle’s configuration. This level of detail in testing procedures is increasingly relevant for modern, high-performance vehicles, ensuring that reported figures are genuinely indicative of their performance under varied driving conditions. The transition from NEDC to WLTP signifies a move towards greater accuracy and transparency in vehicle emissions and fuel consumption testing, providing consumers with more reliable information.
