Great feedback on the fuel filter. How many miles did you have on your truck when you changed it.Hey all, wanted to give some insight on my fuel filter change. I thought 30,000 miles was a little long for any type of filter so I decided to go ahead and change it. I am glad I did. It was black. There wasn't anything odd floating around in the cup but it was clearly a little rough. I am far from a diesel expert being this is my first one but for 30$ and 20 minutes of my time, it was worth it. I was noticing my fuel mileage was starting to drop a bit. 22-23 on the highway seemed to be a little low from last fall. Is there anything else I should check? Air filter is clean, tires are properly inflated...my driving is mostly highway. I do have a fiberglass cap on it so I guess that's not helping. Let me know your thoughts...thanks!