Oil pressure

[97GSTspyder]

So tonight i finally got around to changing the oil in my new GST. I have no idea what kind of oil was used in it before, I assumed full synthetic. So anyway I got Mobil 1 10w-30 full syn, new filter. Changed the oil, started her up, let the oil circulate for a few minutes, shut her down and fill the oil back up to where it should be. Got in it and i noticed that my oil pressure at idle is a little lower than before. Before the change, oil pressure at idle was a hair above 25 on the gauge. Now that i changed it, it's around 15-20. As rpm's rise, so does the pressure (like it should)...But i'm just wondering what would cause the drop in pressure? I was thinking MAYBE the previous owner had Lucas in it. From what i know, Lucas raises oil pressure a tad. Also, would there be a difference in pressure because of the oil? Like regular compared to synthetic.

Any other ideas?

[gthompson97]

don't put lucas in!!! i've had nothing but problems with that shit, it's too think for our small motors. the oil in it before might have been regular and now that you put sythetic in, that COULD be causing the problem, but who knows, it's too late now to switch back over.