I have a 03 HCH as well, but I only have 22,000 miles on it and I'm getting around 45mpg. My concern with the car was as it got older the mpg would go down. It looks like that is the case with your hch. I'd like to hear from some other hch owners with that much mileage on it. I guess there could be a number of things affecting your mpg, like your battery being almost worn out. Do you noticed that you are getting any assist when you accelerate? I get almost half of my bars in my assist column to turn on when I accelerate onto the highway. Your battery could be dying. The warranty lasts until 80k and you are about to hit that. Could this be it?