This fall I bought an old Ford Ranger 4wd with 2.8 at salvage auction. Got it running ok, seemed acceptable oil pressure just driving it down to get mail or letting it sit and idle until it warmed fully, but oil pressure started dropping to 5psi at hot idle after highway driving. Threw can of aftermarket oil thickener in it. Minute change not worth mentioning. Today I had to go do laundry and stopped at AutoZone. Looked at oil display and saw Valvoline SAE60w straight weight oil. Meant for racing. Never saw it before. Had seen 50w racing oil long time ago, but nobody much carried it. About heaviest oil you ever saw was 40w or 20w50. Anyway this 60w is as thick as many aftermarket additives and lot cheaper. Actually looks thicker than 80w90 gear oil. Got 4 quart, new oil filter and qt of Lucas Oil Stabilizer just for heck of it. Had used Lucas in a manual tranny before and it does quiet a noisy one. Never tried it in an engine as I usually fix or ditch engines in poor enough shape to need such. Well, I did the oil change after getting home with engine hot to get out as much crud as possible. Oil draining out was black after just couple hundred miles since my first oil change. Previous owners for sure didnt believe in maintenence. Hot idle oil pressure is now 35 to 40 with the Lucas and racing oil.. Wow, I'm impressed. My question, do you think engine will even turn over with such thick oil after outdoor temp nosedives tonight? ;-) I maybe sorry for my experiment but it was fun and dont think this engine had long life in store with that 5psi oil pressure anyhow. Wouldnt hesitate to run it with super thick oil in summer though.