I've taken two long (300-350 mile) trips in the past two weeks. In both cases, I filled up with gas before I left and filled up on arrival. I ran in HV mode with charge showing 15 miles. HV mode maintains charge at approximately same level while cruising. It pulls battery power going uphill and restore charge going downhill. I got 41.5 gas MPG on all four legs. (This was with same amount of charge at beginning and end of trip.) I am happy with this, and this seems reasonable given the EPA highway rating is 40 MPG. However, the trip computer showed that I got 45.5 - 47.5 MPG, which is 11-12% higher than actual. As others have reported, the range calculations were completely wacky. At one time I showed over 650 miles range. I called Honda to report this bug, and they said to take it to dealer. I hope that they fix this in a software update. Apparently the Accord and Odyssey support OTA updates, but the Clarity does not. I find this odd for their flagship new technology car. As an experiment, I also ran it until the low fuel indicator lit, and then was able to put in 6.4 gallons. Since tank is only 7 gallons, the light does not turn on until you are down to 0.6 gallons. I found the Clarity to be a very comfortable and quiet highway car. Driving across the Smokies, I did hear the ICE revved up as it climbed the grades, but I maintained 70-75 with no problem. You can also hear the ICE when running over 80 on flat road, but at 70-75 it was barely noticeable. Oh, and I love adaptive cruise. That was big factor in wanting a new car.