Pryor to my trip I was getting 30.74 mi/gal combined city and highway. Actually using the ECO mode( versus just the economical riding indicator)
"FEAM" (Fuel Economy Assistance Mode)
on the trip brought it to 42.42 mi/gal (90%highway).
I doubt that FEAM is responsible for a jump from 30 to 42 MPG. It is more likely other factors. Generally, people report that FEAM will improve usage only by about 10% (sometimes a bit more). Anything else could be explained by lots of other factors- type of mileage, weight, exact type of fuel, filling practice, temperature, humidity, tire pressure, total weight, amount and direction of wind, seating position, windshield configuration and position, type of roads, how much and often you accelerate, average speeds, elevation, etc, etc...