Took a trip to St. George Island FL from Atl last week. Loaded truck, three full sized folks. Had a new tank, usually get 43-44 mpg not trying too hard but keeping the speed on the hi-way down to the 60-62 range (the point at which I see the mileage start to drop at hi-way speeds). I was anxious to get there and put it on 78-82 mpg on 2 lane and 4 lane roads mostly, NO traffic at all, A/C most of the time. The mpg's just kept dropping until the finally figure was around 36.5. Got simular results on the way back under simular conditions. Back in Atl now, new tank, mpg back to the 43-44 range. (12k total miles on '05 HCH). Clearly not made for "get me there quick" w/o the trade of mpg. Not unexpected but thought others new to the car might like to hear of the experience.

PS: saw another HCH the moment I hit the Island......BTW Oct on the Gulf works out very well...........

Pete

As is the case with any vehicle that moves through air, the faster you go, the more our atmosphere exponentially tries to slow you down and the harder the engine has to work to keep you at 80mph resulting poor FE. I would have to say that going that speed in a sub compact sardine can with other people in the car is a little outrageous...but that's only my opinion, no disrespect intended. A Benz S600 would be more appropriate/safer for the occasion.....

Pete, it's funny but you just described a road trip I took in June to a T. Only difference was mine was Jacksonville to Atlanta instead of the opposite. My mileage was crucified by speeding, AC, passenger - basically everything you just mentioned. Even the range was consistent with mine. At the time I was getting about 46 MPG and the trip ended barely above 40, very similar to the gap you experienced.