Nov
20
How EPA and WLTP Ratings Differ
Electric vehicle (EV) enthusiasts often encounter two different range figures depending on where they are: the Environmental Protection Agency (EPA) rating in the U.S. and the Worldwide Harmonized Light Vehicle Test Procedure (WLTP) rating in Europe. These discrepancies can be confusing, especially since the same vehicle might show different ranges on these two scales. For instance, the second-generation Nissan Leaf has an EPA rating of 151 miles on a full charge, while its WLTP rating is 170 miles, showcasing a notable difference in how each system evaluates range.
Testing Procedures and Their Impact
The main difference between the EPA and WLTP ratings lies in their testing methods. The EPA performs its tests under more controlled conditions with a temperature adjustment that can affect results, typically reflecting a more conservative estimate of real-world driving conditions. On the other hand, the WLTP uses a more dynamic cycle that may yield higher range figures by including higher speeds and a variety of driving conditions. This contrast helps explain why the WLTP often provides a more optimistic range compared to the EPA.