My Escape is very consistent. I've tracked every tank of gas I've ever put into it (yes, that is the very definition of obsessive compulsive behavior).
I'm now at 7+ years and 115,000 miles. For the first 5 years, I averaged almost exactly 21.5 mpg. For the last 2 years, it's dropped to almost exactly 20.5 mpg. I can live with that.
Interestingly enough (um, at least to me), my '76 MGB get 21 mpg week in and week out, almost all highway miles. 4-speed, non-overdrive, so that hurts the highway mileage. Plus, it's burdened with 69 (yes, 69) pieces of pollution control devices. I'm swapping out to dual SU carbs in the next month or so, which will eliminate the rest of the pollution controls (I've pulled about half off already), and raise the hp from 62 to about 95. I'll bet it raises the gas mileage to about 25 mpg as well.
Oh, the MGB took 2nd place in it's class at the Jaguar of Buffalo car show 2 weeks ago. Of course, there were only 3 cars in our class... :yahoo: