Flow with different filters

Status
Not open for further replies.
Joined
Mar 20, 2015
Messages
11,465
Location
Virginia
One interesting note is there is quite a difference between different brands of oil filters when it comes to flow rate. Wix claims 8-11 gpm vs a Mobil 1 which is 3 gpm. The larger M1 110a has a flow rate of 5.5 gallons per minute. I know an average flow rate is 3-4 gallons per minute for most motors. Question I have is does a flow rate of 8-11 gallons per minute give any advantage over a lesser one? If and when the motor is pushed very hard aka 5k rpm plus does a higher flow rate help more in that circumstance?? Just curious about this stuff.
 
Last edited:
These claims of X GPM of flow by the manufacturer doesn't qualify the spec. For it to make sense they need to say X GPM at Y PSI delta-p with Z oil viscosity.

Keep in mind that oil filters are typically 1/15 the flow resistance of the engine.

The only time a more resistive filter effects flow to the engine is when the oil pump hits pressure relief. A more restrictive filter can cause the oil pump to hit pressure relief with less flow output compared to a less restrictive filter. But the filter would have to be very restrictive to make an oil pump hit pressure relief when the oil is fully hot and thin. One of a few good reasons not to go nuts with the throttle until the oil is at full temperature to ensure good flow to the engine.
 
Isn't flow governed by the physical characteristics of the oil system and engine design. If an oil filter can flow more it would just mean there's less chance of the filter restricting the flow.

If the area of the holes, louvers or slots in the tube exceeds the area required the shape has no effect.

Oil filters, in general, have more potential flow that would ever be required.

I could be wrong on everything.

How ya doing, bbhero? The heat broke here and we don't have hurricanes.
 
Originally Posted By: bbhero
I know an average flow rate is 3-4 gallons per minute for most motors. Question I have is does a flow rate of 8-11 gallons per minute give any advantage over a lesser one? If and when the motor is pushed very hard aka 5k rpm plus does a higher flow rate help more in that circumstance??

There are a lot of high performance engines that flow way more than 3~4 GPM. The threads about Subaru engines showed some of the turboed models can flow around 12 GPM max.

A less restrictive filter will have less delta-p and will give more headroom before the pump hits pressure relief. Less delta-p also means more headroom before the filter's bypass valve opens. Keeping the filter bypass valve closed and keeping the oil pump pressure relief valve closed are both good things.
 
That makes sense Zee0six. I know that the 3-4 gpm was at a normal operating level aka 1500-3k rpm. I appreciate your answer and thoughts in this. It all makes sense to me. I like learning new things on here.
 
Oneyejack I have been doing rather good. On my birthday the other day I felt really good at work. Last evening I felt very good at work as well. Really nice to feel pretty much normal and be able to walk out of work feeling very close to as good as when I walked in. I hope that you have been doing good. You are in my thoughts often.
 
Hi bbhero,

Sounds like you're succeeding in being healthy. Sometimes it's more work but feeling good is hard to explain when you've expected less.

I'm out of the hospital and cutting up some pine trees with a chainsaw. Feeling exhausted after a few hours work feels really good. I think not being able to sit still has been good for my health. I'm not much for pills.

I was thinking about oil filters because of you and I can't figure out what I would expect if I changed something. Would increased flow or higher pressure do anything for a DD that the factory setup doesn't already do? I just buy the same oil filters and that's that. I use a Mobil 1 M1-209 on my V8 4Runner and a NAPA Gold 1392 on my 84 Civic.
 
Originally Posted By: OneEyeJack
Would increased flow or higher pressure do anything for a DD that the factory setup doesn't already do?

Only if the more restrictive filter causes the pump to hit pressure relief. On most DD type vehicles, any well known brand of oil filter is going to flow just fine. There was a rumor going around for years that the PureOne was "restrictive" because it was so efficient. But someone got data from Purolator that showed it had only 5 PSI of delta-p with 12 GPM of hot oil flow.

My Z06 has on-board digital oil pressure and oil temperature sensors. I used 4 different brands of oil filters and saw zero difference in oil pressure vs RPM vs oil temperature measurements from idle to near redline. That's because the positive displacement oil pump never hit pressure relief with hot oil at 200 deg F. If the pump is not in pressure relief then all oil volume leaving the pump goes through the engine.
 
One benefit of using a less restrictive (lower resistance) oil filter is you get more power and fuel economy. Small, but definitely there. Oil pumps are a parasitic loss in an engine, so if you use an oversized filter with less resistance, you actually boost peak power and MPG too.

With positive displacement oil pumps, flow rate will be about the same, but with less power loss with lower resistance to flow.

About flow rate, remember those bypass oil filters (not MicroGreen, but the Amsoil-types) actually do reduce flow rate to the engine, by around 10% or so less flow. Something to think about. Rarely a problem I assume, unless there is some kind of problem with the hydraulic actuators in variable valve systems.
 
My Cummins 6.7 engines flow 16 GPM of oil. Probably explains the big of a filter, and huge stand pipe. Combine that with its 50 psi relief valve (in block), and any filter going onto one of these engines really has it's work cut out for it.
 
Exactly DoubleWasp. My step father's Ford F 250 had a big whomping oil filter on it. I bet that filter held 2 qts of oil at a time. I think the oil capacity of the truck was 15.5 quarts.
 
In the league of regular passenger vehicles, the Powerstroke 7.3 has the largest oil filter by a good margin.

Filter looks like a coffee can, and you could probably stick a graffiti marker into the center tube without touching the sides.

Makes a Cummins filter look kinda small.
 
Originally Posted By: oil_film_movies
One benefit of using a less restrictive (lower resistance) oil filter is you get more power and fuel economy. Small, but definitely there. Oil pumps are a parasitic loss in an engine, so if you use an oversized filter with less resistance, you actually boost peak power and MPG too.

Yep, so small that it couldn't be measured in the noise level of HP and MPG variables. There's typically only a few PSI difference in max delta-p between oil filters. If you run the HP formula for flow & pressure for a 2 PSI difference you'll see it's very miniscule.
 
For me, it's much ado about nothing for street applications. Here's why:

I've cut open numerous brands and constructions of oil filters over recent years,
center tubes with holes, slots or louvers, lots of holes some with way less!
Filter bases with as few as 4 holes some with 8, large holes, others much smaller!

The biggest restriction is the tight clearances in bearings that will float
on an oil film of .001" or less at every moving part!

This is the restriction that the oil pump builds pressure against at the end of the day!

The delta-p of any national brand filter in a healthy engine won't be a factor or we'd
have all seen oil related engine failures.

The worst-case scenario for delta-p would be an engine with bottomed out main bearings
with oil flow so high the oil pressure collapses and turns on the oil light at idle
with a full oil pan! I had this happen, so I raised engine idle and changed from 10W30
to 20W50 and drove that Chrysler Slant-6 225ci engine with 180,000 Miles another 2 years!
In that case as bad as it was, the delta-p of the filter still wasn't a factor!

The thing to remember, delta-p will vary with oil flow, the lower the flow even with a
steady pressure from the oil pump, delta-p will drop. At 'zero' flow static pressure, the
delta-p of all filters good or bad will be zero!


Manufacturers can measure and characterize a filter in many ways, it doesn't mean it'll effect
your daily drive negatively, thank god for that!

If you're running a dragster at 8,000 RPM or more, then you want a rock-catcher filter
with a 100 micron screen!

I'd be more concerned with filters with separated pleats and tears allowing unfiltered oil
then delta-p !! Once we walk through the rationale, it's OK to put the issue to bed.
 
A clogged filter to the point of going into bypass at low RPM is more concerning, especially at high engine RPM when pump volume is highest. In that condition there could be a pretty large volume of oil being directed away from the engine if the pump goes into pressure relief many 1000 RPM early due to a clogged filter.
 
And remember, "most" oil pumps turn 1/2 the crank speed. The newer engines have dual-stage oil pumps. Less drag at lower RPM's, more flow at higher RPM's.
 
Originally Posted By: oldhp
And remember, "most" oil pumps turn 1/2 the crank speed. The newer engines have dual-stage oil pumps. Less drag at lower RPM's, more flow at higher RPM's.


I am not saying you're wrong, but this is news to me.

Can you give a few specific examples? Any links or photos? Data?

Just want to understand if I'm in the dark here (wouldn't be the first time in my life ....)
 
Variable displacement oil pumps have been out for a few years now. Good example them being used is in the GM EcoTec3 engines on the trucks.
 
The dual stage or variable output oil pumps put out less flow at higher RPM to try and save parasitic HP loss and increase gas mileage. Another attempt by the car designers to squeeze out every last sliver of MPG to meet CAFE goals.
 
Status
Not open for further replies.
Back
Top