I have a 07 5. 9 G56 quad 4x4 stock (3000) miles. Just took my first road trip pulling my approx 8500lbs. camper and got10 mpg at 65-70 mph. I have never got better than 11. 5 around town. I also took a 400 mile trip emty and got 15. I read the thread on how good the trucks did with the G56 is this becouse my truck is so new. Will it get better. THANKS