"Idiot light" vs. Oil Pressure Gauge
I am pretty sure I noticed my oil filter going into bypass mode on cold starts last winter.. the Pressure gauge read 5-7 PSI lower than normal until the oil warmed up a little.. That was on a slant six with 80K. Recent oil pan removal for dipstick soldering, and paint. Valvetrain looked clean when I had adjusted the valves.. The oil might have been synthetic, and I had not owned/driven the truck very long. I should have just changed the filter as a test, but I did not think of it, and changed the oil as well. Problem solved..
My point being I want an oil pressure gauge... AND and idiot light that is bright enough for me to notice...