oil pressure?

I read somewhere one the posts yesterday that oil pressure should be nowhere below 14 at anytime for an xj. Mine is a 98, 4.0L. After driving on the highway (70-80mph), then coming down to idle at a stoplight or something, the pressure will drop almost to the bottom of the gauge, like maybe 3-5 psi and the engine runs just barely rough. But until i stop, the pressure is in the normal range. I've watched the temp gauge and its not doing anything out of the ordinary. Should i be concerned about this? if so, any suggestions? Thanks!

If you kind of read between the lines of the other thread, you might note that the stock gage is not considered all that accurate and that brand of oil filter apparently makes a big difference. After ensuring that you have a good quality oil filter and fresh oil, if the rig still drops way low, I would connect a mechanical oil pressure gage and see what it says. Good way to check the accuracy of the stock gage.

The spec is 13 psi at 650 RPM idle. If yours idles rough, it may not be idling at the specified 650 RPM and the oil pressure would thus also be lower. If your at 40 or better at highway speeds and not at zero when idling, I think you're okay.

alright ill check that out. thanks guys