Oil Pressure Ranges

[BRICH1260]

Hey guys, posted a question earlier today about my oil sensor as I thought I might have a problem. It has led to another question, I have a 5.7 GXI-J with about 300 hrs on it. While paying attention to my gage, I noticed a good amount of flexation on my digital readout. At idle speeds , < 1K rpm it was down around 15-psi and at cruse, 3500 rpm it would get up to 30-40 psi. No alarms were sounded. Is this normal? What are normal readings?

I am use to my cars pressure gage which never falls to the lows that I was seeing. Is there that much difference between a boats oil pressure and a cars?

 

[dypcdiver]

My boat when at normal operating temp runs 15psi at idle 650rpm, at cruising 3000rpm 40 to 50psi, at full throttle 4800rpm 60psi. It has been like that since new, now 600hrs. I change oil every season and have always used Mobil S (now called 2000) as semi synthetic 10- 40 W.
I do not think you need worry. Well I don't!

 

[BRICH1260]

Then I`ll rest a little easier. Thanks for your help.

 

[skydiveD30571]

Those sound like normal readings to me as well. My 5.0GL has very similar numbers.

Your owners manual states that your minimum oil pressures are:
~1000rpm - 6psi
~2000rpm - 18psi
~4000rpm - 24psi

That shows me that the fluctuation is normal.