I've had this truck for two years. One of the first things I did was to hook up a mechanical oilpressure gauge; the factory one was kaput and I like units on my gauges, not just L and H, thank you very much. Cold idle about 85psi, cold revs over 100, warm idle 25-30, cruising around 40-60. But in the last six months or so, pressure has been a little lower: 75-80 cold idle, as low as 10 warm idle. Is there a good reason this might've happened, or do I have a failing oil pump, or just a crappy Sunco gauge?