Out of curiosity, when are you guys checking your pressures? As oil gets hotter, it gets thinner and your pressure falls. So if you were just driving on the highway with the rpms pegged at 3,000 the whole time (traveling at about 80 mph) it makes sense for your oil pressure to be a little lower than at normal temperature. Same can be said for if you were just beating on the car and redlining it....its gonna show a lower idle oil pressure because the hot oil is thinner. I'd almost guarantee in both of these scenarios if you let the car idle for a few mins for the temps to stabilize the pressure would go back up to where it should be. This is why its important to pay attention to your oil pressure at the other specified rpms as well as idle.

This is what i noticed on my own personal 2008 350z with 58k miles. My idle psi will be around 10-12 (maybe 10 in the summer and 12/13 in the winter) psi after i just beat on the car or drove for 80 mph for a long period of time... But if im not driving aggressively it will be at 15 psi. My other psi's at different rpms were all in spec regardless of how the car was driven.

Do you think i need to worry about doing the galley gaskets at this time or i should wait until it gets worse?

 

Sounds like you are fine just keep an eye on it. Nissan specs the oil pressure at 176F (80C) and that should be when you are using 5W-30. The HR does have an oil temp sensor that can be read with NDSIII. Its an android application for use with an OBDII Bluetooth or maybe wifi dongle. It's similar to torque but is Nissan specific.

One more thing the in car oil pressure gauge isn't that good as you are doing considerable amounts of estimation as it only shows 30psi increments. If you are truly worried I would highly recommend getting a inexpensive oil pressure gauge to verify the pressure. Harbor freight has a decent gauge for the price.