Quick question for the group. For my 98 4.6 f150, I am nearing the end of my first change to GC. Right now i'm at about 4100 miles with GC and a motorcraft filter. Would it be safe to go to 5k on this combo then change the oil and filter? Anything beyond 5k might be pushing it without lube control I imagine, also what are the limits of the motorcraft filter on mileage? To tell the truth I just checked the oil today and it still looks very clean, it has only darkened a bit after 4100 miles and that really impressed me. I think i can do 6 month oil changes with this combo and some lube control.