Not that I'm complaining, but after changing my oil at the weekend to Mobil Delvac-1 5W-40 from Mobil-1 15W-50 my oil pressure is indicating slightly higher on the gauge. Its only about a needle-width's higher but noticable. I didn't change the O-rings on the filter stem (I do that every 3 changes) so I can't explain it by anything I did differently.
Does Delvac have some mysterious thickening quality
I would have thought that going from 15W-40 to 5W-40 if anything the oil pressure would be slightly lower.
As I said, I'm certainly not complaining, just curious