8 Top GM Oil Filters Cut Open - Fram, Bosch, Wix, Purolator, AC Delco

[Robvette]

8 popular GM filters compared. All of these filters are very good and imho 2 are outstanding.

This is the filter spec is used on my stroked LT1 383 powered 1992 Corvette (which is why I was interested in doing this comparison), and, this is a super popular filter, used in millions of GM cars.

Full Disclosure: my 1992 Corvette has a pretty rare Lingenfelter built engine and it is amazing. I feel very lucky to be the owner of this car. It sees numerous track and autocross days each year, and it's 30+ years old, so choosing the very best available filter and oil for optimal performance and protection is super important to me. I was using a Mobil 1 filter (a good option) and, thanks to doing this comparison, moving forward I will be using a Fram Titanium filter paired with Mobil 1 Supercar 5w50 oil.

All 8 Filters are ultimately made by 2 parent companies: First Brands (Fram, Champion Labs - AC Delco) and Mann-Hummel (Purolator, Wix, Bosch, Mobil 1).

 

[fantastic]

So the AC Delco is probably made by First Brands. Is the Ultra the non-metal backed version you have? Wix & Bosch are not really known to be 20@99% filters. I agree about the Boss. If it had a better rating...

What's the PSI bypass on your car & what does Fram say they're built in bypass is?

 

[Robvette]

Bosch says it's 99% at 20um, and I emailed them to confirm:

 

[Robvette]

@fantastic the Ultra 3980 is not metal backed, Endurance and Titanium are. I'm not certain of the bypass psi on the car or filter. and re the Boss - I was hoping it would have a better rating but I emailed them to double confirm:

 

[fantastic]

WIX has proven, on BITOG and previous data on their website, that its efficiency is terrible. I appreciate you putting the video together though. It's nice to see filters cut open & dissected. Fram is a great filter & they have proven that.

 

[Brian123]

8 popular GM filters compared. All of these filters are very good and imho 2 are outstanding.

This is the filter spec is used on my stroked LT1 383 powered 1992 Corvette (which is why I was interested in doing this comparison), and, this is a super popular filter, used in millions of GM cars.

Full Disclosure: my 1992 Corvette has a pretty rare Lingenfelter built engine and it is amazing. I feel very lucky to be the owner of this car. It sees numerous track and autocross days each year, and it's 30+ years old, so choosing the very best available filter and oil for optimal performance and protection is super important to me. I was using a Mobil 1 filter (a good option) and, thanks to doing this comparison, moving forward I will be using a Fram Titanium filter paired with Mobil 1 Supercar 5w50 oil.

All 8 Filters are ultimately made by 2 parent companies: First Brands (Fram, Champion Labs - AC Delco) and Mann-Hummel (Purolator, Wix, Bosch, Mobil 1).

Lt1, 383, did you ever get the Cylinder Heads Flow Tested?

Dyno Numbers, at the Flywheel or on a whatever Dyno where the wheels spin? Chassy Dyno?

 

[Robvette]

Lt1, 383, did you ever get the Cylinder Heads Flow Tested?

Dyno Numbers, at the Flywheel or on a whatever Dyno where the wheels spin? Chassy Dyno?

This was a Lingenfelter Corvette package (first image) so 440hp ish.

Lingenfelter dynos every engine but they didn’t still have my dyno record when I inquired when I bought the car 2 years ago.

It actually went to Lingenfelter twice and the second time got .060 pistons and rings so it’s a tiny bit more than a 383.

 

[ZeeOSix]

Re: Video talking about no seal vs a seal on the leaf spring to end cap on the Titanium vs the Endurance. If there was enough dirty oil leaking at that interface to make a difference, the Endurance could not test at an efficiency rating of 99+% @20u as Fram shows. Sure, seeing a seal there makes people feel fuzzy, but ISO 4548-12 efficiency testing shows that it doesn't matter.

 

[Brian123]

This was a Lingenfelter Corvette package (first image) so 440hp ish.

Lingenfelter dynos every engine but they didn’t still have my dyno record when I inquired when I bought the car 2 years ago.

It actually went to Lingenfelter twice and the second time got .060 pistons and rings so it’s a tiny bit more than a 383.

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440 HP at the Flywheel sounds very good, what Coolant are you using in this Engine?

 

[Robvette]

Re: Video talking about no seal vs a seal on the leaf spring to end cap on the Titanium vs the Endurance. If there was enough dirty oil leaking at that interface to make a difference, the Endurance could not test at an efficiency rating of 99+% @20u as Fram shows. Sure, seeing a seal there makes people feel fuzzy, but ISO 4548-12 efficiency testing shows that it doesn't matter.

There’s no way they add an actual seal there for fuzzy feelings. 0.0001% of consumers are cutting open their filter even looking for a seal in this location. And they’re not advertising it.

Having any hole in the bottom plate is unnecessary (see Bosch, Mobil 1, Boss, etc.), but, if you’re going to have a hole there adding a legitimate seal is without question a superior design.

 

[Robvette]

440 HP at the Flywheel sounds very good, what Coolant are you using in this Engine?

I’ve not changed the coolant in this one. I have Prestone in my other Corvettes (not the GM orange - just their all-vehicle formula). Is there a coolant you recommend?

 

[ZeeOSix]

There’s no way they add an actual seal there for fuzzy feelings. 0.0001% of consumers are cutting open their filter even looking for a seal in this location. And they’re not advertising it.

You think the Endurance could have an ISO 4548-12 efficiency of 99+% @ 20u is there was all kinds of dirty oil leaking past that interface of the leaf spring to the end plate? I don't think so.

 

[ZeeOSix]

Having any hole in the bottom plate is unnecessary (see Bosch, Mobil 1, Boss, etc.), but, if you’re going to have a hole there adding a legitimate seal is without question a superior design.

Fram uses that design because it's easier to make a common leaf spring with intetrated bypass valve than it is to put a bypass valve into the end cap.

 

[fantastic]

What octane do you run? just curious

 

[Robvette]

You think the Endurance could have an ISO 4548-12 efficiency of 99+% @ 20u is there was all kinds of dirty oil leaking past that interface of the leaf spring to the end plate? I don't think so.

Yes, I do think the Ultra could achieve 99% at 20 with a very very small amount of unfiltered oil making its way around the leaf spring.

The point of me cutting open all of these was to choose examine the details of their designs. Every filter I cut open is a good filter, the seal on the bottom of the Titanium is just one of the qualities that make it the very best of the bunch imho.

 

[OVERKILL]

If you are finding Titaniums with the wire backed media, stock up, that's probably old stock, they are being transitioned to the same media as the Ultra. I have several that I got from former member RodKnock as well as a nice sized collection of OG Ultra's that I got at Canadian Tire (cleaned them out).

 

[ZeeOSix]

Yes, I do think the Ultra could achieve 99% at 20 with a very very small amount of unfiltered oil making its way around the leaf spring.

20 micros is 0.0007 (7/10ths of one thousands of an inch). Based on Fram's own ISO efficiency data, the Ultra, Endurance and Titanium are all 99+% at 20 microns. If the lack of a fiber seal between the leaf spring and end cap makes any difference it would have to be below 20 microns. Only way to know would be to see ISO 4548-12 efficiency data down to 5 microns. Bring.

The point of me cutting open all of these was to choose examine the details of their designs. Every filter I cut open is a good filter, the seal on the bottom of the Titanium is just one of the qualities that make it the very best of the bunch imho.

Yeah, it "looks" like a better design and it certainly can't hurt, but it's essentially a "feel good" design aspect in this case because nobody can say it makes it more efficient below 20u without real data. If no fiber seal on the end cap impacted the efficiency much, Fram would have put a fiber seal on the Endurance like they did on the Ultra. I would run the wire backed versions all day long because all are rated at 99+% @ 20u which is about as good as it gets with consumer level spin-on and cartridge oil filters. Anything better than that is basically hair splitting.

 

[Robvette]

20 micros is 0.0007 (7/10ths of one thousands of an inch). Based on Fram's own ISO efficiency data, the Ultra, Endurance and Titanium are all 99+% at 20 microns. If the lack of a fiber seal between the leaf spring and end cap makes any difference it would have to be below 20 microns. Only way to know would be to see ISO 4548-12 efficiency data down to 5 microns. Bring.

Yeah, it "looks" like a better design and it certainly can't hurt, but it's essentially a "feel good" design aspect in this case because nobody can say it makes it more efficient below 20u without real data. If no fiber seal on the end cap impacted the efficiency much, Fram would have put a fiber seal on the Endurance like they did on the Ultra. I would run the wire backed versions all day long because all are rated at 99+% @ 20u which is about as good as it gets with consumer level spin-on and cartridge oil filters. Anything better than that is basically hair splitting.

If you’re only concerned with a filter’s ISO 4548-12 claim, then just run the Tough Guard.

It filters just as well as any of the others - provided you’re sticking to 15k OCIs or less.

 

[ZeeOSix]

If you’re only concerned with a filter’s ISO 4548-12 claim, then just run the Tough Guard.

Filter efficiency, no failures during use and price are the main things that really matter. Doesn't matter how they are designed in order to get there.

It filters just as well as any of the others - provided you’re sticking to 15k OCIs or less.

The TG isn't 99+% at 20u, so it therefore isn't quite as good below 20u if that matters to anyone. But yes, it's a good filter in terms of efficiency and mileage rating for the price as long as someone isn't hung up on "fiber end caps".

 

[Robvette]

If you are finding Titaniums with the wire backed media, stock up, that's probably old stock, they are being transitioned to the same media as the Ultra. I have several that I got from former member RodKnock as well as a nice sized collection of OG Ultra's that I got at Canadian Tire (cleaned them out).

I have 5 Titaniums for the Lingenfelter. 5 years from now I’m sure there will be something else awesome available