I have a 2010 F350 diesel with 25K miles on it. Hauling a 5th wheel around and have been getting ~10MPG hauling. Recently noticed the truck will hesitate/bogg down as I give it more gas going up hills. Along with that, my MPG has dropped to ~7MPGs. I had the fuel filters replaced at 20K miles. I add the Ford reccomended diesel fuel additive to my gas at fillups. Plan to go talk to dealer but looking for ideas 1st. Thanks!

 

Was it in regen when that was happening? I can feel a definite loss in power driving up a steep hill when I'm in regen--even when empty!

 

No, truck wasn't regen'ing while going up hills but it was regen'ing often and for longer than normal in general. Turned out to be an EGR valve that needed to be replaced. All kinds of black soot built up in there. They tell me bad gas or idling too much would cause this. Not sure where I got the bad gas and I really don't idle that much. Bottom line is that it was covered under warrantee. Will see if that takes care of the issue.

 

sounds like the EGR was stuck open.