OK, so I have approx 700mi on my HCH, and according the the trip computer I have averaged 43.5MPG. My daily commute is 100mi round trip and approx 50% highway.

On my way in today (prior to getting on the higway) I was averaging approx 51mpg per the trip computer, which is typical from what I have seen. When I got on the highway I put the car through it's paces. The Tach was reving up to a 5500RPM and max assist was also occuring, then I gently started easing off. When I settled in @ 65MPH, the trip computer showed me to have lost less than 1MPG overall, no biggie. I am cruising at 65MPH, and no matter what I tried, the Instantaneous FE meter was displaying 7bars or the equivalent of 35MPH. I think I could have gotten that from a gas engine '06 Civic....

The entire 25 miles or so on the higway I tried to go increase the FE. I went up in speed and then back down again, I lowered the speed to 62MPH overall, I tried using cruise. The FE on the trip computer just kept dropping....

So the factors that were apparent to me were:
1) I opened it up on the on ramp and held it there for about 30 seconds. I don't think this should have any effect, but since I have not done it before I thought I would ask.
2) Humidity was up, which again, I do not think this would have much effect until I use the A/C, which I did not engage at all.
3) The direction I travel on the highway is directly west, prior to that it is mostly N, N/W, so perhaps this was a small factor (wind?)
4) Lastly, the Batt condition was the lowest it has been, at 4 bars at the beginning of the trip, up to 5 bars before getting on the highway, and 6 bars shortly after I was on the highway, so the regen was a little more apparent than usual...

I have never seen such low FE numbers prior to this trip, so that is why I ask. My guess is a cross wind and additional charging was the culprit in the decreased FE.

I hope the more experienced here will share their thoughts....