Haven't been on in a while. No matter how I check it my mileage be it from the tripometer, computer or by hand my 04 4X4 with 35's is still turning out anywhere from 18 to 23. 3 mpg. As it has 200. 000 miles on it i was thinking of buying a newer one but 2 wheel drive. The reason for this adventure is I am disabled, getting in and out is becoming a problem and i realy do not need the 4X4 anymore(less things to go wrong and have to fix IF they do). But I will never give up the Cummings. I have read that the new ones do not get as good mileage, but, will the 2 wheel drive (5. 9 or 6. 7) get as good of mileage as the 4x4.