Here is what I found on a 65 and a 75 miles per hour freeway. You may be surprised! I could EASILY beat the cruise control by at least 5 MPG consistently. This was mostly flat highway south of Phoenix.

With the cruise set at 75 miles per hour, the gauge went up and down with every undulation in the road and with every car that passed me or that I passed, etc. It varied mostly between ~20 and ~50 MPH, spending most of it's time around 37 MPG. This went on for over 20 miles before I decided to try my foot.

What I found is that you can plant the edge of your foot against the center hump and with slight "tilts" of the ankle get very precise positioning of the accelerator pedal. Above 45-50 miles per hour, the FE seemed to be pretty constant for any fixed pedal position. That is, I could drive at any FE I wanted! Most interesting is that I could pretty much hold 75 MPH with the FE fixed at nearly 55 MPG! The speed would vary between 72-76, but the milage held as steady as my foot.

With more playing, I found it was very easy to hold a fairly steady speed between 55 and 65 miles per hour, but the faster I went, the more the speed varied with the fixed foot position. The peak FE was clearly above 65 MPH (getting over 60 MPG), but less than 70 MPH. This was with just under 1000 miles on my TCH. Also, I noticed I needed about 2 MPG less to hold speed with the AC on than with it off (and with the outside temp being around 100 for this trip through the desert, it didn't stay off very long!).

At the conclusion of this 200+ mile outing, my average was 39.7 MPG, but it would have been under 35 had I kept it on cruise the whole way.

-- Alan