Here is my question. I don’t have a specific reason for asking this question it kinda just popped in my head while driving and I couldn’t come up with a straight answer…

So is oil pressure dynamic or static? I’d think it is constant because of what the gauges I’ve read on the forums but here is what I’m having trouble coming up with. Engine speed isn’t constant so why would oil pressure be? I would think that a machine spinning at a high RPM would need a higher flow of oil than a slower spinning one. So since engines have variable speeds why isn’t oil pressure variable?

Do auto makers just set their pressures at the highest tolerable level and call it a day? That kinda seems inefficient even though that may get the job done.

Anyone care to explain the answer and why?

 

Constant and static are the same thing. I presume you mean static or dynamic. Anyways, I would assume it's dynamic since the engine needs of a motor can and do change depending on the parameters.

 

Oops yeah, dynamic. Here's my thing though I always see people saying, "with such and such oil my pressure is at ### but when I switch to yada yada its drops/rises to ###." Never when I'm at idle I have ### PSI but on the interstate at 80 MPH I'm reading ###. That's what leading me to assume it may be static but I don't know, so I'm here asking you guys.

I mainly want to know because I'm a little worried about my oil return line and the pressures on it but I just want to know about oil pressure in general and if it changes at all.

 

Of course it changes. That's why the gauge changes at diff rpms, diff temps and diff oil weights.

 

Ahh, see I've never heard anyone talk about it at different RPMs. So, I take it that the pressure is just scaled up or down according to engine speed or what? I can see the ECU reading oil temp and RPM but not weights. What triggers the ECU to say the engine needs ### PSI versus just a little bit less?

 

The oil pump isnt ecu driven, so nothing tells the ecu how much pressure to run.

 

your oil pump is timing belt driven. So that means the faster the crank spins the faster the oil pump spins also. which creates more oil pressure the higher you go in the RPMS. It doesnt have anything to do at all with the ECU, it's purely mechanical.

oil pressure can be affected by a few things outside of The oil pump rpm's though. those being mainly temperature of the oil, and viscocity

 

Ahh! I got it now. It makes perfect sence where everything is located then also. (An I'm guessing why a bad install of a crank pully can cause an oil leak.) Thanks guys