I think that you should see a bit of improvement as the 2300 gets broken in and you become more familiar with its optimal operation. Do, however, take note of the fact that from Newport News to the OBX you were operating basically on flat ground and at sea level, which would have given you an advantage to start out with. I also see that you noted that it was windy - the big question is whether it was a headwind or tailwind.
Happy Camping! ///// Richard D.
2006 4x4 Ford 250 SD / 2007 Flagstaff 827 FLS
One very patient wife and one furry child who travels with us. Forty-two years of trailering and camping, and I still have a blast.