I have a 52 mile round trip to work and back home everyday. About half is highway and half city. I never gave much thought to the Sport Mode, tried it once or twice, but for the last month I've used it continually and I've been getting two MPG better with it on. EVIC with Sport mode off has been 21 MPG (EVIC reads about .7 MPG better than actual MPG) and 23 MPG with Sport Mode on. I guess it likes hanging in the higher RPM longer.