New oil & now oil pressure reads differently

So per a recent post on the use of Pennzoil Long Life 15w 40w oil, according to Pennzoil's web page (http://www.penzoil.com/) a very informative page, BTW, they state that the Long Life oil meets not only the latest in diesel engine ratings but also in gas engine ratings, plus, it's designed to hold more particulate material in suspension than other oils. I took the plunge. The first thing I noticed is that the oil gauge reads different oil pressures than it did before, under similar circumstances. Before the gauge would not move much from the high point, but now, at idle, it reads about mid way. It still goes up to full pressure when the tach rises more than a couple of hundred rpm. The car has always used pennzoil.

Is this difference anything to be concerned about??

…tracy