GM Duramax 2020-2021 oil filter vs. 2001-2019 oil filter

[wwillson]

The ACDelco PF2232 was the factory oil filter for the Duramax from 2001-2019. GM changed the Duramax filter in 2020 to the ACDelco PF26, which is considerably smaller. Below is a picture of an unused PF2232 [edit] Fram XG9100 element (from my 2018 Duramax stash) compared to a Mobil 1 210A for my 2021 Duramax. The PF26 is slightly longer, but is similar to the 210A. When I change the PF26 currently on the Duramax, I will cut it open and compare it to the element on the PF2232. Why GM changed to a much smaller filter is beyond me. I'm going to look for a longer filter with M22-1.5 threads, possibly a Baldwin B40150.

The M1-210A was the second filter and was run from 2,500 miles to 9,100 miles. There is quite a bit of machining metal in the filter still, so I'll change the PF26, which it's running now, at 5,000 miles.

 

[ZeeOSix]

Below is a picture of an unused PF2232 element (from my 2018 Duramax stash) compared to a Mobil 1 210A for my 2021 Duramax.

View attachment 74781

The ACDelco PF2232 looks like a Fram Ultra.

 

[Rat407]

It would make to much sense to keep filters the same. No fun or extra money in it.

 

[Jimmy_Russells]

It would make to much sense to keep filters the same. No fun or extra money in it.

They kept them the same for 20 years

 

[Boomer]

Bean counters at the factory. Save a buck on each filter...more profit.

 

[wwillson]

Another thought, at high RPMs and high flow, how could this small filter not go into by-pass? How much volume could this filter flow?

 

[dnewton3]

Wayne - I think you'd be surprised how well any filter (regardless of size) flows.

I suspect that new smaller filter still flows well more than the engine puts out at max pressure and rpm.

Filters (air and lube) are not sized for the beginning of their lifecycle. They are sized for some safe margin past the end of their expected lifecycle.

Think of it this way ... if the filter is expected to flow X gallons at Y pressure at Z rpm, that condition can happen at any time in the filters expected lifecycle. So the "capacity" of the filter when new is typically "oversized", so that as it loads up, it still has the capacity to funcion well as it ages. Filters don't start out at 100% capacity, and then degrade to 75% in 5k miles. They start out at some value well above what's needed, so that as they age with service, they still have the capacity to do their job. Perhaps (my example here ...) they start out with 135% capaicty when new, so they would end at 100% of the needed flow after 10k miles.

Why did GM make the filter smaller? Cost savings most likely. They realized that the filter previously used was grossly oversized and was a waste of money. You're not getting screwed in the application of a smaller filter; you're getting screwed in that GM didn't pass the savings on to you - they pocket the savings. It's not like they dropped the cost of the truck by $X.xx dollars and you felt the relief in your wallet when you bought the truck. But in theory, you'll be able to buy cheaper filters when it's time for an OFCI.

The smaller OEM filter on the new Dmax engines may not have the massive "over capcity" that the old one did, but the new one surely has the capacity to live a full lifecycle (the max of whatever the IOLM would allow) and do it's intended job. If you intend to run extended OCIs with the HPL oils, then perhaps just FCI when the IOLM says it's time, and extend the OCI.

You can "upsize" to a larger filter, but I'll be the first to tell you that you'll see zero change in your wear rates; the filter size is meaningless in that regard - there's no REAL WORLD study data I've ever seen that shows conclusively it matters. Upsizing a filter in this manner is a "feel good" move that lacks any credible evidence to support the notion.

Dave

 

[bullwinkle]

GM seems to like tiny filters in their truck applications-I wish the one on my LS 6.0 was as big as the PF26 one. As long as it doesn't blind off with debris, I guess it's fine.

 

[wwillson]

Wayne - I think you'd be surprised how well any filter (regardless of size) flows.

How can we determine the flow of a filter? I don't see flow data published with the specs.

 

[RDY4WAR]

It's likely a cost-cutting measure with enough assurance that it'll survive the warranty period without increased failure rates / claims. Once the warranty is over, GM couldn't care less about it. At that point, they're far more interested in selling you a new truck rather than keep your old one running.

I like a larger filter for a couple of reasons. For one, more filter area means less pressure drop for the same flow which has to have some impact on filtration efficiency. It increases the engine's oil capacity which can further help with extended drain intervals. It also adds more surface area outside of the engine that could aid in oil cooling. (if that's a concern for the application)

 

[PimTac]

Cost savings plus the idea that there is less waste going into the waste stream.

 

[Job]

You pose good questions. Doing some internet searching, the PF26 is usually more expensive than the larger PF2232. A lot more expensive on some sites.
The 22mm threads are larger on the PF26, quite a bit. That's the main restriction, unless the element is clogged. So it seems they wanted to increase the filter outlet piping size and increase the flow, if the oil pump was also increased. Maybe the engines run cleaner after 2019, it seems they think more media and a taller filter isn't needed to maintain the increased flow capacity.
Actually it depends on the inside diameter of the 22mm versus 13/16" filter mounting pipe. Assuming the wall thickness is about the same the 22mm is going to give more flow at the same pressure.

 

[wwillson]

The 22mm threads are larger on the PF26, quite a bit.

If you convert 22mm to inches you get 0.86" The fraction 13/16" represented as decimal = .81" which gives a difference in size of 0.05", which isn't going to make any practical difference in flow. I understand the wall thickness isn't represented in my calculation, but there is virtually no difference in the wall thickness of the pipe where the filter screws onto the housing.

 

[PimTac]

The flow outbound has to be the same as the flow inbound, right?

 

[wwillson]

The flow outbound has to be the same as the flow inbound, right?

If the outflow is less than the inflow, you have an extremely serious situation!

 

[Job]

If you convert 22mm to inches you get 0.86" The fraction 13/16" represented as decimal = .81" which gives a difference in size of 0.05", which isn't going to make any practical difference in flow. I understand the wall thickness isn't represented in my calculation, but there is virtually no difference in the wall thickness of the pipe where the filter screws onto the housing.

Yes I did the calculation too, of course before posting the first time. The bottom line is the oiling system has more flow capability on the new model, not less. The filter has to be up to it‘s task for that on your truck. Now it’s a very common filter size for many vehicles, like a Fram PH2, XG2. Just trying to help with the rationale for things.

 

[wwillson]

I wish I knew the flow with pressure drop of the PF26 and how much flow the Dmax requires through the RPM range.

 

[wwillson]

I did some searching and found that the L5P oil pump is rated for 21 gallons per minutes, but doesn't say at what RPM, however I would assume that's high speed near redline. At 1,600 RPMs the flow would be around 10 GPM, since it's a positive displacement pump - my guess, but it's probably a reasonably accurate assumption. 10 GPM seems like a lot of flow for this little PF26 filter, but I have no data to back that up.

 

[ZeeOSix]

How can we determine the flow of a filter? I don't see flow data published with the specs.

The ISO 4548-12 test is really the best way ... but of course you can't get that data from the filter manufactures.

Would you all like to see ISO 4548-12 Oil Filter Lab Testing Comparison, Efficiency & Capacity, Pressure vs Flow, Bubble Point, and Burst?

I have this as a “watched” thread, so if you do happen to start a new one, could you put a note or link in this one to direct followers to the new thread? Thanks!! Yes, no problem I can do that.

bobistheoilguy.com

 

[ZeeOSix]

I like a larger filter for a couple of reasons. For one, more filter area means less pressure drop for the same flow which has to have some impact on filtration efficiency.

Yes, less delta-p will mean a little better efficiency if the media doesn't have debris holding power so to speak. It was shown in the thread I just linked in the post above.