[Joshinator99]

Originally Posted by djctoto

Oiled air filter elements have been reported to corrupt MAF sensors. Causing the sensors to read incorrectly. Dry filters while not flowing as well as oiled filters don't have this potential issue

Food for thought

This has been debunked more times than I can count over the past 20 years. It would take a massive over-oiling of the air filter and even when that happens it doesn’t seem to corrupt the MAF signal. I even have a very recent first hand experience on this point. My new JLT filter was massively over-oiled from the factory leaving significant visible oil in the intake tube and TB blade, to the point I needed to wipe it out with a cloth. It had no impact on MAF accuracy. And cleaning the MAF resulted in no difference afterwards either. My wideband tracked everything identically before and after I noticed the excessive intake oil. So I think we can retire that old wives tale.

[NYTMARE23]

Originally Posted by Joshinator99

This has been debunked more times than I can count over the past 20 years. It would take a massive over-oiling of the air filter and even when that happens it doesn’t seem to corrupt the MAF signal. I even have a very recent first hand experience on this point. My new JLT filter was massively over-oiled from the factory leaving significant visible oil in the intake tube and TB blade, to the point I needed to wipe it out with a cloth. It had no impact on MAF accuracy. And cleaning the MAF resulted in no difference afterwards either. My wideband tracked everything identically before and after I noticed the excessive intake oil. So I think we can retire that old wives tale.

I agree! I've had K&N oiled filters on intakes for 3 vehicles I've owned(combined 12 years of oiled/re-oiled filters). Whether they were new filters with the kits or filters that I have cleaned and re-oiled, I have NEVER had any issues with oiled filters messing up the MAF. .

[KingLT1]

My car wanted 3% more fuel going from the standard rotofab with 95mm tb to the big gulp with 103...This is on a Whipple setup that has a 112mm snout with a mild 10-11psi of boost. On a PD car, anytime you can reduce intake restriction you will gain more power through efficiency. But you have to reduce the restriction all the way from the filter to the blower snout. It doesn't do much good to install a bigger intake on a stock blower snout / 87mm tb setup.

That being said I have run both dry and oiled filters. I like the dry filters...it's just a preference. In the past I have seen transmissions get burned up from oil getting on the maf and skewing air flow data which throws off the torque calculations for transmission shift pressures. This was more of a thing back with gen 3 and 4 LS trucks for some reason. Either way you just have to make sure the filter is not over oiled is all.

[Joshinator99]

Originally Posted by KingLT1

My car wanted 3% more fuel going from the standard rotofab with 95mm tb to the big gulp with 103...This is on a Whipple setup that has a 112mm snout with a mild 10-11psi of boost. On a PD car, anytime you can reduce intake restriction you will gain more power through efficiency. But you have to reduce the restriction all the way from the filter to the blower snout. It doesn't do much good to install a bigger intake on a stock blower snout / 87mm tb setup.

That being said I have run both dry and oiled filters. I like the dry filters...it's just a preference. In the past I have seen transmissions get burned up from oil getting on the maf and skewing air flow data which throws off the torque calculations for transmission shift pressures. This was more of a thing back with gen 3 and 4 LS trucks for some reason. Either way you just have to make sure the filter is not over oiled is all.

Agreed on the intake restriction, I’m surprised this conversation still comes up all these years later lol. GM went to a 10% bigger TB on the ZR1 for a reason and that was only 100 crank HP more than the Z06/ZL1.

Yeah I had an ‘04 GTO new back in the day and those Gen 3 MAF sensors were different than the Gen 5 stuff…that sensing element was 100% exposed. These modern MAF sensors all tuck the actual sensing element into a “cartridge” housing so I suspect that’s why they’re much more resistant to an over-oiled filter. Just a guess but seems to be the case. My JLT was WAY over-oiled to the point where I was like “WTF!” but it just didn’t matter during our hub dyno session. So if a filter is oiled properly, it should read just like a dry filter in terms of MAF accuracy.

[Joshinator99]

Originally Posted by NYTMARE23

I agree! I've had K&N oiled filters on intakes for 3 vehicles I've owned(combined 12 years of oiled/re-oiled filters). Whether they were new filters with the kits or filters that I have cleaned and re-oiled, I have NEVER had any issues with oiled filters messing up the MAF. .

Yep! Been running them as well since the mid-90’s (what can I say, I’m old lol). Had one in my nitrous’d ‘88 IROC-Z 350 back then haha

[djctoto]

KISS.
A. Is a MAF sensor designed to work with a film of oil on it. Answer - No
B. Is there a possibility that oil from an improperly oiled filter will end up on the MAF - Yes
C. A + B just add together is the answer.

Wether or not it happens depends on too many variables for even AI to predict.
There is no myth to be debunked when there are documented cases of this happening.

[RobZL1]

I think the point is that the MAF element is encased in a Gen V engine. It will not be affected by oil.
Run what you like, oiled or dry. It is inconsequential.

[NYTMARE23]

Originally Posted by RobZL1

I think the point is that the MAF element is encased in a Gen V engine. It will not be affected by oil.
Run what you like, oiled or dry. It is inconsequential.

Exactly! Personal preference.. I'll keep running oiled until proven wrong or I actually start having problems which I don't forsee happening since I haven't had any issues for 12+ years. That said. I'm not ENTIRELY opposed to trying dry, if needed.

[djctoto]

Impossible for the MAF to be fully encased it must be exposed to the airflow to function and is therefore also exposed to any oil that may be present in the air.

[Z OH 6]

Originally Posted by djctoto

KISS.
A. Is a MAF sensor designed to work with a film of oil on it. Answer - No
B. Is there a possibility that oil from an improperly oiled filter will end up on the MAF - Yes
C. A + B just add together is the answer.

Wether or not it happens depends on too many variables for even AI to predict.
There is no myth to be debunked when there are documented cases of this happening.

You have no idea what you're talking about. The likelihood of this happening is slim to none unless a customer re-oils the filter improperly. You can't engineer every product around a customer's stupidity.

[RobZL1]

Originally Posted by djctoto

Impossible for the MAF to be fully encased it must be exposed to the airflow to function and is therefore also exposed to any oil that may be present in the air.

Ok, AI engineer literal guy. You are 100% literally correct. You win. I have to go re-oil my filter now.

[djctoto]

The trade off then appears to be go with an oil filter with even a remote chance that it could screw up your MAF sensor which directly controls AFR's to gain whatever negligible improvement there may be in CFM air flow compared to dry filter where there is no chance of this happening (aside from getting dirty which will happen in either case) or go with a dry filter thereby eliminating the possibility of the critical MAF sensor producing erroneous results.
Don't get me wrong I've used both in the past but I now subscribe to a more simple approach of avoiding any potential problems if it's easy to do so.
Sorry if I alarmed any of the oil filter favorites. But don't worry about it a HP or two is worth it compared to not having to even consider the chance that it could cause an issue, who knows. I'm out of this sillyness.
Take up the discussion with Mishimoto, but what do they know.
Key Considerations
Maintenance: Oiled filters must be cleaned and re-oiled at intervals, as the oil layer is crucial for filtration; an over-oiled filter can potentially harm the Mass Airflow (MAF) sensor, says Mishimoto.

[Z OH 6]

Originally Posted by djctoto

The trade off then appears to be go with an oil filter with even a remote chance that it could screw up your MAF sensor which directly controls AFR's to gain whatever negligible improvement there may be in CFM air flow compared to dry filter where there is no chance of this happening (aside from getting dirty which will happen in either case) or go with a dry filter thereby eliminating the possibility of the critical MAF sensor producing erroneous results.
Don't get me wrong I've used both in the past but I now subscribe to a more simple approach of avoiding any potential problems if it's easy to do so.
Sorry if I alarmed any of the oil filter favorites. But don't worry about it a HP or two is worth it compared to not having to even consider the chance that it could cause an issue, who knows. I'm out of this sillyness.
Take up the discussion with Mishimoto, but what do they know.
Key Considerations
Maintenance: Oiled filters must be cleaned and re-oiled at intervals, as the oil layer is crucial for filtration; an over-oiled filter can potentially harm the Mass Airflow (MAF) sensor, says Mishimoto.

Unquestionably, oiled filters flow better than dry filters for about a 1% less filtration rate when properly oiled. That being said, you probably wouldn't get any arguments out of anyone that has a high horsepower application that could get a dry filter that would flow as well as an oiled filter. Problem is that some of the high performance oiled filters are quite large now in order to keep up with the flow demands of today's really high horsepower engines especially when modified so with underhood space being a premium, it's a bit difficult to get a dry filter that flows as well as oiled filter that isn't 30% larger in size. You can get away with those on lower power engines because the filter size of a dry filter is still large enough to flow the volume needed for an average engine but ultimately, when there's enough power being made, no dry filter is good enough without robbing power, same reason why some REALLY high horsepower drag cars run NO filter at all, less restriction and there's no oiled filter big enough to keep up with those power demands.

[djctoto]

Originally Posted by Z OH 6

Unquestionably, oiled filters flow better than dry filters for about a 1% less filtration rate when properly oiled. That being said, you probably wouldn't get any arguments out of anyone that has a high horsepower application that could get a dry filter that would flow as well as an oiled filter. Problem is that some of the high performance oiled filters are quite large now in order to keep up with the flow demands of today's really high horsepower engines especially when modified so with underhood space being a premium, it's a bit difficult to get a dry filter that flows as well as oiled filter that isn't 30% larger in size. You can get away with those on lower power engines because the filter size of a dry filter is still large enough to flow the volume needed for an average engine but ultimately, when there's enough power being made, no dry filter is good enough without robbing power, same reason why some REALLY high horsepower drag cars run NO filter at all, less restriction and there's no oiled filter big enough to keep up with those power demands.

I never suggested that dry filters could outflow a properly oiled oil filter. If you go back to my original post it was closed with "Food for Thought"
For those high HP applications with folks willing to properly maintain an oil filter it can be the the way to go.
For those who may not a dry filter may be the right choice.

But to imply that an oil filter is foolproof in all cases is just misleading.