Getting ready to change my oil in my 2024 Stingray. Purchased the 0W-40 Mobil 1 Supercar oil and a filter. When I purchased the AC Delco 64 filter, I didn't notice that it was a PF64R. So, I researched what the difference was and found out he following: The internal pressure relief valve is set at 35 psi for the PF64R instead of 22 for the PF64. If I'm reading correctly, once the internal filter pressure reaches the designed pressure relief pressure, the filters starts to bypass the oil in the filter--Not all the oil is being filtered. Not knowing for sure what the higher pressure relief valve would do in the LT2 engine, I purchased the PF64 filter. The PF64R is a bit taller and it seems to weigh more. I assume it is a little bit more robust compared to the PF64 in order to withstand the higher 35 psi. Question--Is there a negative side to installing the PF64R filter with the higher 35 psi pressure relief valve. It would seem that the PF64R would filter all of the oil until the oil pressure reaches 35 psi. I don't know what effect that would have on the LT2 oil system. To add insult to injury, some oil filter venders actual listed the PF64R instead of the PF64. The owner's manual does list only the PF64 filter. Looking forward to your answers and opinions. Thanks

 

PF64R is not the correct oil filter. This topic has been covered countless times. PF64R is the correct oil filter for the Chevy Volt 1.5L plug-in hybrid; it has more robust construction as its designed for 2-year oil change intervals and has to withstand that additional oil soak.

Besides the ACDelco PF64, other high-quality compatible filters that I recommend are:
Mobil 1 M1-114A
Fram XG12060

 

See this link, PF64 Only GM service bulletin on oil filters :17-NA-157
https://static.nhtsa.gov/odi/tsbs/20...42844-0001.pdf

 

IMO a better filter for the C8 is the standard PF64 is the Fram XG12060 Ultra synthetic.

 

This is the filter I personally run (C7 & C8).

 

For me, the negative side is that it is not the recommended oil filter for this application. The PF64 appears in the 2024 Owners Manaul and apparently also the latest part number for it:

25206377

Will is cause a problem? I do not know. But should an engine problem develop, the dealer and/or GM will check for that the proper filter was used. I do not know if the a PF64R would be considered proper, but I do know that the PF64 would be proper. Folks will point out that GM must "prove" that incorrect part (if it is incorrect) caused the problem. But as a practical matter, if GM denies a claim because of an the wrong filter, it will be up to the customer to challenge that. For those reasons I would consider it a negative - and not because I have any particular knowledge that the filter would not work properly.

Using non-Delco filters, many of which are very good, also incurs a risk in my opinion, but I am aware that many do so with confidence.

 

That is the main reason I went out and purchased the PF64 filter. I have no intentions of getting into a pissing contest with GM. I have used other oil filter brands on my previous Corvettes, primarily K&N. I was just curious about the 35 psi vs 22 psi effect on the oil system itself.

 

If you get the Autozone Mobil 1 0W-40 ESP X3 deal it comes with the STP S12060XL filter. While I didn't use it it seemed like a quality filter and the numbering is consistent Fram's oil filter numbering, it is likely made by Champion labs. It has synthetic blend media and heavy construction. I didn't use it because I already had a Mobil 1 filter and the the relief pressure is listed as 15 psi for the S12060XL on the Autozone website but I suspect that is an error, I just didn't feel like calling the 800 tech support number on the box. It appears the Fram 12060 series has the required 22 psi relief pressure while the 10060 series has a 15 psi relief. I'm wondering if anyone else has looked at and/or used one.
https://www.autozone.com/filters-and...directUrl=true

 

It's a good filter, very similar to Fram's line, just not rated for the longer intervals (which most aren't doing anyway) which tells me pleat count is lower. 99% @ 20 micron is about as good as it gets these days. Based on the specs, I'm guessing its using something similar to Fram's ToughGuard media (which I currently run in my Jeeps). If I can't get the 114A next time I order the AutoZone deal I'd consider running this filter instead of my typical XG12060.

 

I'm sticking with the PF64. But this statement in the bulletin is interesting.

"Note: Any aftermarket filter must also have an internal bypass valve opening pressure
specification, element integrity, filtration performance, media particle trap specification
and burst strength that is equivalent to the ACDelco PF64/PF63 filters.

Does equivalent bypass valve opening pressure specification mean "equal", or no lower?

Also, oil filter can fail, both Delco or aftermarket. Some have said that if an engine failure is caused by a failure of the correct filter - it would still be covered by the warranty if it is still under warranty. But, if an aftermarket filter fails, it might not be covered. I do not know if this is entirely accurate, but for me it is an additional risk factor.

 

The whole bypass pressure thing is tricky since it is dependant on the media and the thickness of the oil. The intent is to make sure the engine gets oil if the filter becomes too restrictive but you don't want it bypassing too soon. So a filter with the correct bypass pressure rating but a more restrictive element would bypass too soon as would a bypass valve with a lower relief rating unless it had less restrictive media. So defining the bypass pressure without defining the associated media and oil weight doesn't mean it will work as intended.

Some oil filter companies (like Mobil 1) state that if their filter causes engine damage they will cover it. I haven't seen this stated for the STP filters. I never seen anything in writing from ACDelco or GM stating that if a ACDelco filter causes an engine failure that GM or ACDelco will cover it (but they likely would). GM can't deny warranty coverage just because an ACDelco filter wasn't used, it would have to be shown that the filter caused the failure.

 

Nothing wrong with using the UPF64R filter in place of the PF64. Both AC Delco and GM list the UPF64R filter as fitting the C8. Even my local Chevrolet dealership uses this filter on C8's. It's a better filter in every way compared to the PF64 and the one I've been using for the last 2 oil changes on my 23. I actually prefer the higher flow rate, higher filtration and higher bypass to help prevent unfiltered oil from circulating the system and if GM/AC Delco recommend it I'm sure it's ok despite what the Karen's say.

 

The Karens! LMAO😂🤣 It is true. It will make not one IOTA of difference. I know, I know. "Yoou know more than the GM engineers?" No, but I know the LT2 is what the British used to call a "cooking" engine. Great motor but it is a glorified truck engine with a tiny, baby camshaft and under relatively low stress. I've used ALL sorts of different filters on LS motors in MUCH higher states of tune and it made no difference whatsoever.

 

It is not a psi rating but rather a dpsi which is differential pressure. So it is not bypassing when the system pressure is over 22psi. There has to be enough of a restriction in the filter relative to the change in flow rate to cause a 22psi difference. These filters with 0-40 oil probably never bypass. Fwiw 22psi is relatively high for an oil filter. Many are in the 8-15dpsi range.

I have checked with GM and AC Delco about the the PF64R filter as an option, they both say no.

 

Although I plan to use the PF64, I did find that the Delco parts catalog lists PF64 and PF64R both as fitting 2020-2023. Interestingly, if you search for 2024 Stingray, it returns only the PF64 and says it fits 2023-2024. So, its inconsistent. Furthermore, that same site also lists aftermarket interchange brands. Does that mean GM or Delco endorses the use of those? Folks can feel free to do what they want. I plan to use the PF64.

What did you mean when you said you checked with GM - was that a different source from the ACDelco Catalog?

 

I have never seen the 35 psi relief pressure for the UPF64R confirmed by GM or ACDelco. However it has been listed on 3rd party websites and spread on the internet.

If the bypass pressure truly is 35 psi I wouldn't use it and there is enough doubt right now that I wouldn't use it unless I was in a bind.

 

Reaching AC Delco is not easy, so I called GM and they funneled me to a service division which by application said the PF64 is the only option. I did finally get an email response from ac. I might still have a copy on my work computer which I could post a copy of their response on Monday. I would be more concerned about the compatibility of the two pn#’s if there was a difference in the micron rating. Definitely do not want to decrease the micron rating because that will have a profound effect on the flow rate.

 

Does this bulletin even apply to the C8 which has the LT2 engine? It does not include LT2 in the list of engines - it goes from LT1 to LT4. It also says this:

"Beginning in 2012, the oil pumps began to regulate main gallery feedback instead of
pump out pressure. This means that the oil pump now does not begin to regulate until
pressure is built up to the main gallery. This change reduces the amount of time it takes to
provide oil to the engine bearing and lifters during extreme cold start conditions."

And this seems inconsistent with position of the oil pressure sensor and oil flow for the LT2 engine, in the Service Manual.

The oil is pressurized as it passes through the primary pump and is sent through the engine block lower oil gallery to the liquid-to-liquid
(engine coolant to oil) engine oil cooler. Oil exits the engine oil cooler, past the engine oil pressure sensor, and enters the full
flow oil filter where harmful contaminants are removed. A bypass valve is incorporated into the oil filter, which permits oil flow
in the event the filter becomes restricted. Oil exits the oil filter and is then directed to the upper main oil galleries.

In other words, in the LT2 the oil pressure is measured at the filter input, not at the "main gallery" as described for the applicable engines in the bulletin. I searched for evidence of another oil pressure sensor located further downstream from the filter - such as in the main oil galleries - but did not find any. The only oil pressure sensor is the one mounted on oil filter boss which is described as being before the filter.

Edit: Add - "After more reading I found this, that suggests a possible mechanical/hydraulic based regulation, rather than being based on the oil pressure sensor:
An oil passage at camshaft bearing location permits oil flow to the upper rear of the primary oil pump. Oil is pumped through this
passage and provides hydraulic pressure to the first stage oil pressure cavity in the primary oil pump. Hydraulic pressure in the
first stage pressure cavity regulates engine oil pressure and can help reduce the load on the engine during normal operating conditions."

This would be more consistent with the bulletin which says oil pressure does not start to regulate until there is pressure in the main gallery. So, maybe it would apply if it listed the LT2 engine.



I'm not sayin' that its ok to use a different filter - just pointing out that the bulletin may not be applicable to the LT2.

 

Sorry to open this can of worms again, but I have a question. There is a lot of talk regarding the PF64 with a bypass rating of 22psi and the UPF64R with a bypass rating of 35psi. Where did these numbers come from? I cannot find a single published thing from AC Delco or GM that states a bypass psi for either of these filters. I did read that Rockauto once incorrectly listed the psi on their site for the UPF64R. Does anyone have an actual reference for the bypass psi of these 2 filters other than the 22 and 35 numbers that have been bouncing around on forums for years? Thanks.

 

PF64 @ 22psi is directly from GM; they released a bulletin during the C7 years (see attached).