The only way the econ mode will help is after 40 MPH. And it will help a lot. Below 40 it make the car sluggish and does not improve MPG>I have a 2020 HAH Ex for few months now. I used to have Econ mode on. But out of curiosity I turned it off and still getting high mpg. Now, I don't drive much and temperature changed a lot between these cases. Has anyone done any controlled experiment with comparable environments to measure the differences?