It's been over 5,000 miles since my last oil change. Checked dipstick and found sticky caramel color deposit on the normally immersed portion of the stick. If the stick, which gets wiped down ~12 times/year has brown , gummy appearance then I bet the other interior surfaces are worse.
Would it be a good idea to add an engine oil flush product to the truck after starting, then drive to the dealer ~4 miles away for the overdue
60,000 mile service? Gunk brand flush is ~$5 and I would only have it circulate for 15 minutes before dumping the oil.