Hey Guy's New here and have a question .We have just shy of 19,000 miles on our 2014 eco diesel GC and at the 10,000 mile mark e had oil changed at local dealer .sense then the MPG has gone from high 20's low 30's to High Nothing best I can pull out of it is 24 and that is no change to driving habit's or anything .I'm not new to diesel's so My Question is Could the Idiot's at the dealer put the wrong oil in ? when I ask that question I get told no way it would throw a CEL right away but .I can't take this Low MPG any more .I have a good friend with a eco Jeep and he had the same issue and they changed out the exhaust system and it fixed the Problem . What direction should I go ?Any more I can drive my truck and get better fuel Economy then I can with this thing .