Only thing I hate with these new diesels is the egr and regen crap, the mileage now is horrible from all 3. My buddy had a lifted on 35's 4dr Cummins with 6 speed manual with some mods and it would get 22 highway and 16 city with the lift and tires, his new Cummins (6.7) gets like 12 city and 16 highway and its broken in with a few mods. You can rip the particle filter and other crap out but kiss the warrenty good bye. Our other friend has a new 6.4 Powerstroke that gets maybe 15-16 highway as well, his 6.0 got over 21. But he has red diesel on premises he fills up with
