Cold Air Intake

[Oneshotlucky]

They let too much dirt through, they are among the very worst for dirt allowed to pass. They also fill to capacity faster than most, meaning you have the advantage of freer flow for a short time, then they lose their free-flow advantage, and let dirt through in the process.
This isn't just internet lore - it's based on ISO dyno testing.
Other similar dyno testing showed that the only flow advantage was up in RPM ranges most people would never see unless racing. How often to you drive with your engine running over 4,000 RPM? On a Ford pickup, the advantage was over 5,000 RPM. Even the LS in my chevy didn't see 5,000 very often.

Here is one chart showing the dirt that PASSED THROUGH the filter, into the engine, before the filter reached the restriction limit- it shows that K&N allowed the second most amount of dirt to pass, and it's possible it came in second worst only because it "plugs up" faster.

They are made more for the drag strip where you can clean them after every few passes, and there's not a lot of dust in the air due to the track being kept so clean. Still, a lot of people I see at our annual meets are running paper filters on the track.

So sticking with the OEM filter would be the best route then??

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[CoachA]

Have you searched for the other long threads on cold air intakes?

And no, they help nothing. Doesn't matter the engine, gas or otherwise.

What ever you do - AVOID the K&N filters if you like your engine.

Why say you this about K&N filters?

 

[ShadowsPapa]

So sticking with the OEM filter would be the best route then??

That, or there are good replacements made by other companies - AC-Delco does well, always rated high.

Here's the thing about filters - and I see a lot mentioned about pre-filters as a "solution".
Having worked with HVAC systems and air filtration systems in health care, homes, and even in my wood shop - pre-filters catch the larger chunks.
Take a high-end air purifier as a good example - there's 3 layers of filtering.
There's a cheaper pre-filter that catches the larger sized particals
There's a second filter that catches smaller particles than the pre-filter,
Then there's the final filter. It catches the really small stuff, or is supposed to.
All the pre-filter does is take some of the load off the final filter or filters by stopping larger particles that would otherwise plug up the final filter faster.
If you have one filtering layer, when you stop the really fine stuff, you stop the big stuff too. The big stuff will plug that single filter faster.
If you have a pre-filter, it stops the big particles before they get to the finer filter, keeping it cleaner longer. You can clean the pre-filter as needed.
My lawn tractor is a good example. The main air filter isn't cheap, it does a great job - but running without that foam filter plugs that expensive finer filter faster.
The pre-filter does nothing to stop the small stuff. That's counter-productive. It just doesn't work that way. It protects the final filter from the big stuff and keeps it from plugging as quickly.
If the main filter isn't stopping the fine particles, a pre-filter with larger holes isn't going to help.
THe "holes" in the filters are progressively smaller as you get closer to the engine.

The pre-filter has one purpose -
Stop the bigger particles before they get to the main filter, make the main filter last longer so it can do the job of stopping the small stuff.
A pre-filter does not make the main filter do a better job, nor will it stop the stuff the main filter lets through.

Why say you this about K&N filters?

Yoda?
Because it's true. Check out all of the times I've posted test results, official dyno testing done to ISO standards. They are marketing hype trying to appeal to high performance people who want higher RPM horsepower. People buy into that "cool factor" too easily. It must be good, because I was told it was good and they say it boosts HP.
If you drag race, go for it, if you keep your engine RPM up over 4,000-5,000 RPM and like to clean filters quite often, go for it. You might gain a HP or two, but at the cost of letting dirt through.
Ya know how they can tout better air flow? Bigger holes.
I like my cars and trucks. I'll use filters proven in legit testing, not company sponsored marketing hype, to protect them.
Why use a filter that lets more dirt through for zero gain in performance? Why?

 

[Rattydude77]

Stay away from the filters with oil to my mechanic said there junk and for a cold air intake I just like the sound and look of it other than that like said b4 no HP gain.

 

[MrZappo]

Do none of this hogwash. Take the money and go have a nice dinner. Or buy something useful for the jeep. Virtually anything else.

 

[BlueScapegoat]

Do none of this hogwash. Take the money and go have a nice dinner. Or buy something useful for the jeep. Virtually anything else.

I'll be getting an intake for the sound alone. I'm an automotive enthusiast. If I wasn't, I'd buy something practical. Like a Corolla. Or a used F150, if I needed a truck.

If you're choosing between a nice dinner and a cool sounding intake, then yeah, maybe you shouldn't be spending the money on parts that just make cool sounds. But I choose to choo-choo my way to my nice dinner.

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