Is it possible that at higher altitudes(mountains vs. sea level) oil pressure would be lower?

 

I wouldn't think atmospheric pressure would have any relation to fluid pressure that's built mechanically.

 

I would agree. Atmospheric pressure should have no effect on oil pressure.

 

Look at it this way. Oil pressure is determined by a byoass spring. More pressure on the bypass valve (like say, more air pressure) will naturally make it proportionally more pressure closed.

Don't believe me? What happens when you hook vacuum up to a TPI FPR?

 

The reason I asked is that when I was in the Poconos my oil pressure got halfway bellow the 30 mark with car warmed up. I got worried since I got a new motor and the pressure is normally pretty high. Even in 90 degree heat in NY it stays between 30 and 60, closer to 60.
I'm going back to Poconos this weekend again and I guess I'll see if it drops again.

 

Well, i don't think anything east of the Missisippi gets above 6000 feet. I live in CO at 6500 feet and regularly drive up to 10,000ft. I have never noted a difference in my oil pressure, either at speed or at idle. In our cars, temperature affects OP more than anything else (assuming sufficient volume, of course!)