Global testing norms could cut EV range 10–20%

India is preparing to change how it measures vehicle fuel economy and electric-vehicle range, a shift that could lower the numbers shown on brochures and window labels without any physical change to the vehicle itself. The change centers on adoption of the Worldwide Harmonised Light Vehicles Test Procedure, or WLTP, a global test cycle used to measure fuel consumption, electric energy use and EV range. Hindu BusinessLine reported on May 18 that India plans to replace its Modified Indian Driving Cycle, or MIDC, from April 1, 2027, while also tightening Corporate Average Fuel Efficiency, or CAFE III, rules. Together, those changes could reduce certified mileage and EV range by 10% to 20%, the newspaper said. ### Why would the same car suddenly show a lower range figure? WLTP is designed to measure vehicles under a stricter and more representative test cycle than older laboratory procedures. UNECE’s 2026 amendment document for UN Regulation No. 154 says the rule covers approval of light-duty passenger and commercial vehicles for emissions, carbon dioxide, fuel consumption, electric energy consumption and electric range. India’s current MIDC cycle has long been seen by industry publications as producing figures that are less representative of real-world driving than WLTP. (thehindubusinessline.com) Hindu BusinessLine gave a simple example of what that means for buyers: a petrol car rated at 25 kilometers per liter today could show about 21-22 km/l under the new cycle, while an EV advertised at 500 kilometers could be certified closer to 430-450 kilometers. The report said the drop would reflect the test method, not necessarily a sudden decline in the vehicle’s actual hardware. (unece.org) ### Is this a global rule change or an India-specific shift? India’s April 1, 2027 move is a national rollout, but it is tied to an internationally harmonized testing framework. UNECE’s document describes WLTP as part of UN Regulation 154, which sets uniform provisions for measuring emissions, carbon dioxide, fuel consumption, electric energy consumption and electric range. That makes the Indian change less a new global law than a move to align domestic certification with a widely used global standard. (thehindubusinessline.com) The European Union already uses a related regulatory framework. EUR-Lex says Euro 7 introduces testing procedures to measure fuel and electric energy consumption and battery durability, alongside broader emissions requirements for road vehicles. That means automakers selling across markets are already dealing with a heavier testing and compliance load, even if the exact rules differ by jurisdiction. (unece.org) ### Why are automakers worried about costs as well as labels? Hindu BusinessLine reported that manufacturers may need hardware and engineering changes to meet tighter fuel-efficiency and emissions requirements under the combined WLTP and CAFE III regime. The newspaper said estimated added costs could range from roughly 30,000 rupees to 80,000 rupees per vehicle depending on segment, with items such as improved sensors, upgraded injectors, catalytic converters, mild-hybrid systems and aerodynamic changes among the possible additions. (eur-lex.europa.eu) Economic Times reported in April that Indian carmakers had agreed to draft CAFE III proposals due to take effect from April 2027, with the framework running through 2031-32. That report said the final notification was expected soon. (thehindubusinessline.com) ### What does this mean for EV buyers comparing models? A lower certified range number would affect how vehicles are marketed and compared, especially in segments where headline range is a selling point. U.S. EPA guidance already notes that official fuel economy and EV range figures are based on standardized lab testing rather than each driver’s real-world use, and different test systems can produce different published numbers. (economictimes.indiatimes.com) For buyers, that means a model’s displayed range may fall after April 2027 even if the battery pack and motor are unchanged. For automakers, it means older marketing claims based on MIDC-era certification would no longer be directly comparable with new WLTP-based figures. (epa.gov) ### What happens next, and where will the change show up first? April 1, 2027 is the key date in India’s transition. Autocar Pro and other Indian auto publications reported that the Ministry of Road Transport and Highways has notified the switch to WLTP-based BS-VI testing from that date, while CAFE III norms are also due to begin in April 2027. The first visible effect will be on certification documents, mileage claims and EV range labels for newly tested vehicles. (thehindubusinessline.com) (autocarpro.in)