The variable cylinder management system turns three cylinders off when coasting and on flat surfaces or even slight hills.The change is imperceptible. On mostly flat interstates 70 MPH is 2,000 RPM on three cylinders. (ECO light on) All gas has been fill ups and each fill up has been checked using the A trip counter. (30,000) This driving, includes in/out of city/towns, gives usually gives 24.5 - 25.7 and a seldom 26 MPG. Top EPA is 27. Only once was it 32.6 - all day in the rain under 60 MPH on secondary roads) Only oil/filter changes, air filter and cabin filter (self), and tire rotations.