After taking my beloved truck on the highway for about an hour, for the first time, it began to develop some oiling problems. The oil pressure had dropped significantly over the course of a few days, starting immediately after the highway drive. A bit of research suggested issues with the oil pump, such as broken pickup tube, stuck pressure relief valve, or pump failure. As any of those require pulling the engine, I wanted to try a quick and easy fix: oil change, new filter. I suspected that the intense highway drive may have dislodged sludge in the engine and clogged the oil filter. I took it to Valvoline and had the oil change done, and added a quart of Lucas Oil Stabilizer in case there were problems internally. I also had them grease all the grease fittings and inspect everything. I normally do this myself, but it was cold out and I did not have what I needed with me. They gave me $22 off for being a new customer, simply because I asked. It was awesome. The oil change corrected the oil pressure problems immediately and it has been fine for a few days now. Not sure if it was a clogged oil filter, if the oil was destroyed by the drive, or something else entirely. Assuming the engine will die soon and replacing it ASAP as I do not trust it.