My head hurts by simply reading this thread

[JRHAWK9]

A discussion on the Crosstrek forum about how acceptable oil levels may or may not affect oil pressure.

Here's a little snippet.

Too little oil causes over working of the pump and inadequate oil quantity to properly coat all engine components at the same time for a prolonged period, leading to increased heat from friction that the cooling system must counteract, as well ad increased wear on those parts not properly lubricated.

Model Years 2018 to 2023 - Oil amount and its effect on...

www.subaruxvforum.com

 

[JohnnyG]

Nothin' like a good click.

 

[Jetronic]

A discussion on the Crosstrek forum about how acceptable oil levels may or may not affect oil pressure.

Here's a little snippet.

Model Years 2018 to 2023 - Oil amount and its effect on...

www.subaruxvforum.com

He's not lying that too little oil is bad though overstressing pumps etc isn't what I concern myself about. The question is, how low does the oil level need to get before that's an issue. It's afterall only an issue when the pump starts drawing air, so as little as half a quart in the sump could be enough, or as much as just below the minimum mark could be too little. In fact under some conditions near the max mark may be too little on some designs.

Don't worry about it if you don't get oil pressure warnings. I would however advocate keeping the levels sensibly high to keep contaminant concentrations low.

 

[JRHAWK9]

He's not lying that too little oil is bad though overstressing pumps etc isn't what I concern myself about. The question is, how low does the oil level need to get before that's an issue. It's afterall only an issue when the pump starts drawing air, so as little as half a quart in the sump could be enough, or as much as just below the minimum mark could be too little. In fact under some conditions near the max mark may be too little on some designs.

Don't worry about it if you don't get oil pressure warnings. I would however advocate keeping the levels sensibly high to keep contaminant concentrations low.

It's only bad if their is not enough oil and it starves the pump. Running 4 quarts (in a system designed for 4.7) won't hurt the pump one bit....under normal driving conditions. Racing situations are different. This is a Crosstrek forum, nobody is racing them. Off-camber, off-road situations, maybe, depending on where the oil pickup is.

 

[Jetronic]

It's only bad if their is not enough oil and it starves the pump. Running 4 quarts (in a system designed for 4.7) won't hurt the pump one bit....under normal driving conditions.

Yes that's what I said....

 

[JHZR2]

Less oil would in theory result in higher steady state oil temperatures, since the oil does carry heat away. Higher temperatures would mean lower viscosity, easier pumping. Less film strength perhaps, less hydrodynamic wedge, more wear if the asperities on a surface breach the thickness. Moot if not.

I didn’t click, but if they’re actually splitting hairs between 67-68psi (per the image shown on the link), it’s likely not statistically significant, nor outside of the standard deviation for sampling.

 

[ATex7239]

Considering how many people around here insist on crazy long drains to get out lesser amounts of oil than discussed, I don’t think we are in a position to cast stones.

 

[CleanSump]

Considering how many people around here insist on crazy long drains to get out lesser amounts of oil than discussed, I don’t think we are in a position to cast stones.

Exactly!