I don't know how you're getting only 25mpg.
I drive 70 on the highway and still get 36mpg or so.

Maybe your "street" drivining is bring you down. One thing to do would be to find out how you are doing just on the highway. when you get onto the highway, reset one of your FE gauges (I use trip A for this). Then see what the gauge reads at the end of your highway drive.

Do the same for the city part of your trip.