I had an 07, with the same motor you have (6.7) and I was getting about 13 L per 100 Kl. I now have a 2012 and it`s getting about 14.5 to 15 L per 100 KLs, maybe a little less than 14 on the highway if you don`t put your foot into it. same horsepower little more torque than the truck your looking at, If you do get it, these trucks don`t like to be babied, I run mine with the exhaust brake on all the time.