heyl, how is everyone
i was just thinking to my self about oil pressure, and wondered how much pressure it takes to supply the pressure gauge?
so how much pressure is there with out / and how much pressure with a gauge

and would a top brand name be better,because of this

Been thinkin' a bit on how to answer your question. As most oil pressure gauges are electric as opposed to mechanical (mechanical would require tapping into the oil galley and running a hardline to the dash - not an optimal situation), the real question centers around the sending unit. It is a transducer that is usually found somewhere on the block that intersects an oil passageway. For example, on an Olds 403, it is near the oil fill tube on the front of the block. On a Pontiac 455, it is just above the oil filter. LS1's have TWO: one behind the driver's side valve cover and one near the filter.

One signal wire connects the sending unit to the gauge and the gauge uses that as a comparison between positive and ground to produce a reading.

Anyway, a Stewart Warner replacement sending unit advertises a sensitivity from 6 to 100 psi.

yea i was referring to the standard gauges with the oil that goes up to the gauge
i guess it would come down to quality as well