Okay, so we all know that a Cummins gets better MPG with age. I am at 70,000k / 44,000miles. I have Mobil 1 Devlac in the Crank Case. Have had since 40,000k / 27,000miles.
I had the Cat removed and a High Flow straight trough muffler installed. I installed the AFE Stage 2 intake. There abouts I...