I don't know if anyone can really answer that. There is so much speculation on what is really going on up in the atmosphere, even real "rocket scientist's" can't agree. What I do know is that since installing the sensor, my towing MPG has incresed about 1 MPG+. I have been pulling the fiver for the last couple of weeks, and can't really say what an empty truck may do. However, I pulled today in the flats of Kansas with the wind blowing steady at 30 mph+ and I still got 8. 9 mpg. With this truck, this is great!!