I had a T2000 that got the same mileage. Then came DEF, new EPA stuff and my mileage has dropped into the 6's. I also had few empty miles pulling 40,000lbs of paper both ways on a dedicated trip. As an aside, that run was 1,125 each way. Paper mill paid me to run paper to a different mill to make up shipping shortage and do the same on the way back. It was cheaper to do this than pay the union to start up a production run. Both mills are now gone as the union refused to see the writing on the wall and make concessions. Kept their pay by holding tough but only for another year or two then the mill was torn to the ground and their pay ended up $0 but they showed the company who was boss. Hope it was worth it.