Table of Contents
Have you ever wondered why the advertised range of an electric car differs depending on the country you are in? Homologation tests vary from one continent to another, influencing the figures displayed by manufacturers. Let’s dive into the behind-the-scenes of these international protocols to understand these differences.
The 3 must-know facts
In Europe, the WLTP (Worldwide Harmonised Light Vehicles Test Procedure) cycle has become the standard since 2017. Designed to be closer to real driving conditions than the previous NEDC cycle, it is conducted in a controlled environment with a fixed ambient temperature of 23°C. The test, which lasts 30 minutes, simulates different driving situations, from city to highway, with specific speeds for each. This protocol aims to give consumers a more realistic view of their vehicle’s range.
In the United States, the EPA (Environmental Protection Agency) cycle is known for its rigor. This protocol includes a series of urban and highway tests, conducted until the battery is completely discharged. It also uses a mathematical correction method to refine the results. This cycle is often considered the closest to the real experience of drivers, offering a more reliable estimate of daily range.
The CLTC (China Light-Duty Vehicle Test Cycle) is adapted to driving conditions in China, where urban congestion is common. As a result, this test emphasizes low speeds, with an average of 28.96 km/h. This approach may explain why cars tested in China often display generous ranges. The test consists of three speed phases, but the maximum speed remains limited to 114 km/h.
Japan uses an adjusted version of the WLTP cycle. This test largely omits the highway phase, deemed less relevant, as the maximum speed on most Japanese roads is 100 km/h. The driving phases at 56 km/h and 76 km/h thus constitute the majority of the cycle, reflecting local conditions.
Vehicle homologation tests have evolved over the years to adapt to new technologies and consumer demands. The NEDC cycle, used in Europe until 2017, was criticized for its lack of realism, leading to the adoption of the WLTP cycle. In the United States, the EPA has implemented a strict protocol to ensure results closer to reality. In China and Japan, tests have been adapted to meet local specificities, reflecting the driving habits and road infrastructures of each country.