US: EPA has updated fuel economy test in drive for more accurate mpg labels image

The difference between official figures from automakers and the ones experienced by the drivers in the real world has always been a subject of debate when it comes to fuel economy.

Now the US Environmental Protection Agency has opted to unveil tweaked procedures for a crucial section of the fuel economy testing process that has been blamed for some of the carmakers’ struggles in recent years. The new procedure concerns how automakers will calculate road load values in coast down tests, used to assess the rolling resistance and aerodynamic drag of vehicles as they slow from 70 mph to a stop on a straight, flat track. Those same values are then used to program dynamometers the companies use to compute fuel economy ratings using the traditional EPA test cycle.

Chris Grundler, director of the EPA’s Office of Transportation Air Quality, said the new tweaks should lift the accuracy of fuel economy labels, while also making clarifications on how the agency wants the tests to be done. “It will be more accurate,” Grundler said. “Both the EPA and the automakers have a common cause to make sure that customers are getting the best information.”

The upgraded procedures come at a time when Ford, Mercedes-Benz and Hyundai-Kia were forced to issue corrections of fuel economy labels on numerous models during the past two years after errors were made on the coast down test. Additionally, the EPA will also have meetings in the next few months with the automakers to discuss the testing operations after issues arose with a loophole that gives carmakers the possibility to use the same fuel economy rating to multiple nameplates.

Via Automotive News