Fluid & Filter Preferences Explained - Jeep Gladiator 3.6L V6

[Maximus Gladius]

So scientific ISO testing means nothing?

How do you know that nothing wore prematurely? Maybe you'd have gone a lot farther with proper filtration?

The fact the K&N plug far earlier than any other filter, leading to restricted intake means nothing?

Do I need to post all of the K&N test images again?

fine for racing when you rebuild frequently anyway, or for when you don't mind constantly cleaning just to keep the air flow on par with a paper filter - but nothing I like will run one.

The only “scientific testing” I’ve done is have the lab tell me how much air intake dirt is in my oil. If my numbers showed the same or better than your paper filter, what would that say?

I don’t run mine to the point of being plugged. I monitor it, hold it up to the sun light…you know, do a good visual on it, if I need to clean it, I will. It’s not a filter that gets thrown in and forgotten. The times that I’ll clean it early is during forest fire season and the air is thick with smoke, enough where the news reports tell people if you have breathing issues, to stay indoors and after a lot of salt has been spread out on the roads and when the weather has melted and dried up the ice and what’s blowing around is that fine salt in the air, I’ll clean it out but like I said, my lab numbers show what you see with yours.

K&N goes in everything I love. In fact I gave one to my daughter and son and I got to see tears of joy and gratitude knowing they were telling me they recognized how much I love them. (At least that’s what I gathered from their tears)

Sponsored

 

[ShadowsPapa]

The problem is - "you can't tell by looking", and, the K&N is the second WORST at cutting air flow. It can't handle as much dirt before cutting air flow down below acceptable. So - sure, it will run, but it's also cutting air flow faster than a good paper filter.

It's open wider at first, but fills up faster and closes down flow faster than anything except the Amsoil in these tests.

In other words, I bet to maintain the same airflow as mine, you would have to clean yours several times before I need to replace mine. Yours will cut air to the engine a lot faster than mine. You just won't realize it's doing that.

 

[Maximus Gladius]

The problem is - "you can't tell by looking", and, the K&N is the second WORST at cutting air flow. It can't handle as much dirt before cutting air flow down below acceptable. So - sure, it will run, but it's also cutting air flow faster than a good paper filter.

It's open wider at first, but fills up faster and closes down flow faster than anything except the Amsoil in these tests.

In other words, I bet to maintain the same airflow as mine, you would have to clean yours several times before I need to replace mine. Yours will cut air to the engine a lot faster than mine. You just won't realize it's doing that.

I think AC Delco ran this test. There’s no filter better than them in the whole world?

 

[ShadowsPapa]

I think AC Delco ran this test. There’s no filter better than them in the whole world?

nope, an independent tester. Many of us in the classic car world know those filters hold up.
There's better out there, for sure - but to test every possible filter? These are tests of the most common/most popular.
I believe Project Farm did something themselves, it wasn't as scientific using real world dust particles and high-end equipment meeting ISO standards, but comes up pretty much the same.
There's a guy who tested the K&N on a Ford on the dyno, and showed there was no performance gain unless you ran 6,000 RPM all day long. And at that, you'd need to constantly clean it because they plug up quickly. The amount of dirt they can handle is far far less than other filters.

 

[g2020]

Just to clarify what I think you’re saying here, and may I raise something you’re not saying, this paragraph is bringing attention to the oil that’s visible in the photo that rubs up next to the “oiled K&N” so are you attributing the intake oil residue being caused by the oil leaching from the K$N?

This understanding would be incorrect as the oil residue seen in the photo is directly related to the “fresh air IN” tube that clips into to intake tube after the air filter. Many others have posted photos with much concern that there are pools of oil at that spot that drip out the “fresh air in” line and has nothing to do with a K&N filter. A simple test that everyone can enjoy doing, including the most seasoned individuals here can be done by unclipping that line and look into the connector, we all will see oil there, including the anti-K&N’ers.

I too use K&N oiled filters and have since the 80’s when I terrorized the streets with my first vehicle and I’ve never had an engine blow up or wear out prematurely because of it. …in fact my sodium/silicon levels in my oil analysis reports would rival the same numbers of the paper filter reports others have shown here. At the end of the day, if the K&N haters ever broke down and decided to try it, or maybe installed one by accident, they would be ok, like the rest of us.

(disclaimer: K&N filter has to be oiled correctly. No dunking of said filter in a pail of oil is allowed and would void my most humble opinion noted above)

Good question. You noticed that I reported observations without entering (or exiting) the off-road engine air filter debate. I posted the photos because I thought that the evidence would help some (on-road / daily driver) folks make a decision.

As for the oil residue, I don't know whether it was caused by oil from the K&N filter. However, I just removed my filter for cleaning & oiling, and there was zero residue (after having wiped away a very small amount last fall).

For other folks considering K&N, don't be creative in the cleaning & oiling procedure. Follow the instructions (available online) and be careful not to over-oil the filter. The trigger-spray (not pump-spray) cleaner and aerosol oil are the easiest to use. I am tempted to post my step-by-step instructions here or in a separate post, but I said that I wouldn't and will keep my word.

Here's my disclaimer again (quoting myself, I know):

"Note: Based on the findings of some experienced members of this forum, an oiled reusable engine air filter may not be the right choice for a vehicle that is frequently taken off-road or otherwise exposed to dusty conditions on a regular basis"

 

[Maximus Gladius]

nope, an independent tester. Many of us in the classic car world know those filters hold up.
There's better out there, for sure - but to test every possible filter? These are tests of the most common/most popular.
I believe Project Farm did something themselves, it wasn't as scientific using real world dust particles and high-end equipment meeting ISO standards, but comes up pretty much the same.
There's a guy who tested the K&N on a Ford on the dyno, and showed there was no performance gain unless you ran 6,000 RPM all day long. And at that, you'd need to constantly clean it because they plug up quickly. The amount of dirt they can handle is far far less than other filters.

Tell you what…. Instead of me saying that it would “appear” this “independent tester” has stocks in the company or lives next door to AC Delco owner or has married his daughter, let’s not go there.

In stead, if we can start by recognizing that your dirt levels in your oil analysis, with your paper filter is the same numbers I see with my oiled K&N, because it is true AND if your saying that the dust and gritty stuff my filter is allowing through is wearing out my engine prematurely, why don’t we compare bore scope pics of #5 cylinder walls to see what scaring and wear we have. Would that be scientific enough?

There’s some reason you shot out of the shadows like a flaming spitting viper like you did. I think I scared you. The other thing I think is that one of our prestigious leaders is going to tariff the crap out of paper filters and you’ll be forced to use a K&N and ….youll be ok.

 

[ShadowsPapa]

Tell you what…. Instead of me saying that it would “appear” this “independent tester” has stocks in the company or lives next door to AC Delco owner or has married his daughter, let’s not go there.

In stead, if we can start by recognizing that your dirt levels in your oil analysis, with your paper filter is the same numbers I see with my oiled K&N, because it is true AND if your saying that the dust and gritty stuff my filter is allowing through is wearing out my engine prematurely, why don’t we compare bore scope pics of #5 cylinder walls to see what scaring and wear we have. Would that be scientific enough?

There’s some reason you shot out of the shadows like a flaming spitting viper like you did. I think I scared you. The other thing I think is that one of our prestigious leaders is going to tariff the crap out of paper filters and you’ll be forced to use a K&N and ….youll be ok.

Scared? no. Honestly - How? Why? One person isn't going to scare me on something like this with all of the time I've researched and info I've saved up.
Even if someone came up with something to the contrary and absolutely PROVED everything I have was incorrect, beyond a shadow of a doubt - I'd not be "scared" - I'd grab the new info and run with it.

(Tip - watch those last lines as some other posts were recently deleted due to touching into politics. Hate to see that happen. No need at all. Don't want to see trouble..... and some could jump on that and oh, boy. )

Here's a breakdown from Google on it:

Paper Air Filter Advantages:
Dust Filtration:
Paper filters are generally considered to be more efficient at filtering dust and other particles than K&N filters.

Cost:
Paper filters are typically less expensive than K&N filters, both initially and when replacing them.
Potential Issues with K&N Filters:
MAF Sensor Contamination: (eh, I'd ignore that part - generally disproven)
K&N filters use an oiled filtering element, and oil can potentially build up on the MAF sensor, causing issues.
Dust Filtration:
Some tests suggest that K&N filters may not be as effective at filtering dust as paper filters.

Testing Methods:
The ISO5011 test is the gold standard in air filter testing. It's used by every major vehicle, engine and filter company in the World to design and rate their air filters.

Ok, enough on the google summaries........
Comparing "bore scope" images would be worthless - you should know - because of all sorts of other variables - oil used, oil change interval, heat of oil, heat of engine, lengths of drives, frequency of drives, loads on the engine and more.
We would need to consider the types of dust we typically run into based on where we live, time of year and so on.

This railing was clean as can be - pure white, before our last rain. Seriously, this came down with the rain - wow:

That was in the air, washed down with a single 1/10th inch of rain.

Anyway, the point is, yeah, we could compare images of the bores - but what's that going to show? A whole lot of various conditions that added up to get to where each was.
You can run identical air filters in two engines and one is going to show more bore wear, perhaps even some scoring or other damage, depending on other factors. Detonation can cause bore damage (oh, how well I know that one)

Do check some of the Bob is the Oil Guy threads........ not a lot of love for the K&N filters, all stating the same reasons - allowing fine dust.

Use whatever you want, it truly is your truck. I'll use what I know and what's been proven as it's my truck. To this day - never an engine or transmission failure on anything I own (well, the T5 did blow a bearing after 160,000 miles of ABUSE)
So I'm sticking with it.

 

[g2020]

Notes from the OP:

1. Most of the replies to this thread relate to the type of engine air filter (paper or oiled cotton)
2. The engine air filter debate will never end
3. If you decide to use an oiled cotton filter, review post #20, if necessary, for basic maintenance advice

4. Other product preferences in the original post (post #1) are either OEM or best-in-class
5. All fluid preferences in the original post meet or exceed manufacturer specifications
6. An expanded list of options is available in Links to Prices

7. Although they can be handy for getting started on a topic, beware of Google AI results because they can be partially or flat out wrong (about meeting manufacturer specifications, in some cases); always confirm using manufacturer documentation
8. As a case in point, Google AI results needed to be edited in post #22

 

[ShadowsPapa]

Really don't know what the point to this was to begin with. Read the damned book.

"Best in class" can be very subjective as well.
Unless you read some engineering test results and other really fun stuff - it's pretty much what people believe.
Some of the fluids mentioned - I'd argue against them being "best in class" based on actual wear test results and the experience of some others out there.

It's your chosen fluids and parts - and that's pretty much it, sorry, but....... if one follows the owner manual, there's never much of a need for anything else. It protects you from anyone suggesting you used something that wasn't up to par with what the vehicle maker says.

Also be VERY careful with the "exceeds" as far as longevity. That can get you into trouble. There is never a case I'd go above and beyond what a manufacturer says with any fluids. There's a lot of marketing, and a lot of variables involved. For one company to say their protections last 50% longer than any others - be very wary.

There should be no need for anything other than the book.

People really should only take that as list of things you have chosen - especially not what's "best in class". I can show numbers disputing that point on at least two items there.

 

[Maximus Gladius]

There should be no need for anything other than the book.

People really should only take that as list of things you have chosen - especially not what's "best in class". I can show numbers disputing that point on at least two items there.

My take from the reading of the list of products itemized by g2020 is strictly those that purport to carry certain designations as outlined in “the damned book” (I feel your pain, I hate it too. It’s what got me in trouble in the first place back in 2021 AND it’s what landed a great big boot up my a$$ and shown the door when I asked the GM to read certain sections of it and to clarify its meaning.)

“Best in Class”… and of course this product or that product out performs another…

You know these tests are all done by “independent testers” so they must all be right in their testing, why, because all these test machines that blow or suck have to be held to strict guide lines and certifications and all made the same, enduring the same conditions.

I think what would produce an iron clad test that would stand above all the others would be to put all the “independent testers” in one room and give them one rule. When the door shuts, they all have 30 min to play this game and when the door reopens, only one person must remain standing and that guy’s report is the one that stands.

Otherwise, it’s all marketing.

 

[ShadowsPapa]

“Best in Class”… and of course this product or that product out performs another…

I could point to two items where "best in class" is very subjective, and not an absolute, nor do they "out-perform" certain others. I can point out testing where they actually don't excel.
That's my point - "best in class" - depends on who you ask, who is saying it as some tests contradict that.
But then we get into the religious "who's xxxxx is best". And I've got enough people blocking me already (up to something like 10 so far! Must be a record) and it really won't matter. It's the internet. And it's a religion.

Even oil and air filter testing, if you look at the variables, a manufacturer can actually specify particle sizes! Amazing that a filter that's about 2/3 the size of a stock filter on a car I know of is supposedly good for 20,000 miles.......... wow, I'd never think of that even on the stock filter size with the modern filter materials (many newer oil filters don't even use paper - not talking the 3.6 - but it is still related)

People can of course use whatever they want, and if they vary much from the manufacturer's guidelines in any area - "longevity" or "meets xxx specs" (when they don't put it on the product label, but their people state it does elsewhere) then you have a risk.

 

[g2020]

Aftermarket preferences, other than engine air filter, in original post above:
In response to replies since post #23

This is a restatement of my aftermarket winners. The oil filter and the T-case fluid did not earn a special designation, such as "writer's pick", in my post on Links to Prices because at least one other competing option is just as good. Price was the determining factor in only one of the choices (T-case fluid).

Whether these are called "best-in-class" or something like "wicked-awesome winners", I am confident in these products. I leave it up the folks who read our posts to click on manufacturer specs and Links to Prices to see requirements and options for each fluid or filter. The lists of options in Links to Prices cover most of the obvious suspects (plus Super Tech as a value brand, whenever possible), and each list is a "class" of fluids or filters.

"Meets or exceeds" (stated in post #23, item 5): Emphasis on the word "or".

Owner's manual: It's great, but it doesn't contain everything that we need to know. As mentioned in manufacturer specs, the internal dealer spec sheet (for trailer towing) and the MOPAR VEHICLE LUBRICANT & CHEMICAL CATALOG (for a crystal clear presentation of coolant material standards) are also required to gain a full understanding of what should go into a Gladiator.

Restatement of aftermarket preferences:

4 & 9. Differential fluid: AMSOIL and RED LINE beat the others on compliance with manufacturer specs. AMSOIL Severe Gear wins based on its service life statement (see section 4 or section 9 in the original post for an explanation of service life as it applies to a Gladiator). SEE TABLE IN SECTION 1.3 OF Links to Prices. Also see "Additional Comments on Published Compliance", below.
5. Motor oil: Mobil 1 EP and five others beat three others on compliance with manufacturer specs. Mobil 1 EP wins based on its mileage warrantee (subject to OEM limits of 10K miles or one year for normal driving and 4K miles for severe/off-road use). SEE TABLE IN SECTION 1.5 OF Links to Prices.
6. Oil filter: Mobil 1 EP was chosen because it is the same brand as, and made (with a matching warrantee) to be paired with, Mobil 1 EP motor oil (subject to OEM limits of 10K miles or one year for normal driving and 4K miles for severe/off-road use). SEE LIST OF OPTIONS, WITH RATINGS, IN SECTION 1.6 OF Links to Prices.
8. Radiator fluid: PEAK and ZEREX beat the others on compliance with manufacturer specs. PEAK Purple wins based on its mileage and duration guarantee. SEE PEAK Coolant AND SECTION 1.8 OF Links to Prices.
10. Transfer case fluid (and manual transmission fluid): All four options comply with manufacturer specs. Valvoline ATF+4 wins based on price. OEM service intervals. For the warranty statement, my post on Warranty Coverage. Changing the transfer case fluid is so easy that buying low and changing more often simply makes sense. SEE LIST OF OPTIONS IN SECTIONS 1.9 AND 1.10.2 OF Links to Prices.

Note: Engine air filter is out-of-scope in this reply. A lengthy discussion of engine air filter type (paper or oiled cotton) is provided in previous replies to this thread and in many other threads.

Additional Comments on Published Compliance

• Each aftermarket fluid specified in the original post, including AMSOIL Severe Gear gear lube, meets manufacturer specifications
  • Compliance is stated on the label for Mobil 1 EP motor oil, PEAK Purple coolant, and Valvoline ATF+4 transfer case fluid / manual transmission fluid
  • For AMSOIL Severe Gear gear lube, compliance is stated on the product data sheet (PDS)
    • As an online extension of the product label, the PDS is a second form of published compliance
    • SAE 75W-85 meets MS-A0450, SAE 75W-140 meets MS-8985, both grades (for friction modifier) meet MS.10111, and both grades meet API GL-5
      • Although it was unnecessary, I confirmed compliance with each material standard (MS-number) in a phone call with the AMSOIL technical team in November 2024
        • They also stated that the friction modifiers will not harm the differential
    • Compliance statement from the AMSOIL Severe Gear PDS
      • "Use in differentials...requiring...API-GL5...or other GL-5 based specifications from vehicle manufacturers, including...Chrysler"
      • Footnote: No affiliation with or endorsement by Chrysler is expressed or implied

 

[ShadowsPapa]

Basically, a list of your personal preferences and why you personally chose them.

Could have been a lot less like an engineering document or college thesis.
But maybe you are a technical writer of documents for equipment of some sort!

I like amsoil for engine oil (second or third choice for me) but will never use it in a differential subjected to towing stresses (based on observations here in the forums (where someone had a failure) and tests I've seen)

Yeah, if you use the Mobil filter with their oil - it's a crazy warranty. I bought some of their filters for one of my cars since I run their oil in it. I never ever go that long on a car that sits so much, but still the coverage is crazy good. It's also a unique filter material on that style of filter - too bad can't get it for the JT.

 

[g2020]

Basically, a list of your personal preferences and why you personally chose them.

Could have been a lot less like an engineering document or college thesis.
But maybe you are a technical writer of documents for equipment of some sort!

I like amsoil for engine oil (second or third choice for me) but will never use it in a differential subjected to towing stresses (based on observations here in the forums (where someone had a failure) and tests I've seen)

Yeah, I've done a lot of technical writing. In the case of the Gladiator, I enjoy learning everything I can. For example, I had never heard or read a bad thing about AMSOIL Severe Gear until today. Now you have me curious.

I think that people (who don't know almost everything) like to see what other people are using. That's the point. If you post (or send to me by DM) a list of your top picks (with part numbers) that are different from mine, I will reconsider. After I did some more research earlier this year, I changed my preferences on coolant (to PEAK Purple) and T-case fluid (to Valvoline).

 

[Hootbro]

I understand what you are trying to do, but I think it really is just a orgy of information that gets lost on most people and there is never a consensus in any oil or service fluid related thread past what the standards/specifications are.

You are writing for a 0.01% audience.

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