Dry Performance Air Filter recommendations please
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From: Durham, NC
Yes but the aftermarket ones usually flow the air with less resistance so your engine isn't working as hard to pull that "same amount" of air thru. So you are getting better throttle response and IMO more power freed up. Less resistance=air moving quicker=quicker response. Some may argue that it is just seat of the pants feel but I have had 3 fords that were stock and all have had a k&n drop in and then 2 were upgraded to intakes later. My 97 2.3l ranger got better gas mileage and I didn't have to downshift as much to get up hills but noticed no better acceleration. Just on hills I had to downshift from 5th to 4th before, the engine wouldn't drop as far in rpms so I wouldn't have to downshift. My 04 f150 heritage 4.2l got driven for 1.5 years total and driving around the same areas averaged 18.9mpg, with k&n drop in it got 19.9 and a little better acceleration and also not as much downshifting as before, then I put a k&n cold air intake on it and all 3 improved even more. I was getting consistent 22-22.5mpg using the same gas pump every time. My 08 I have now, I didn't keep track of mpgs that much but from what I remember was around 17 combined with stock and k&n drop in. After a few weeks I installed the k&n intake I bought for my 04 and it definitely helped in power and mpgs. My scangauge has showed me between 18 and 19mpgs on my 20 mile drive to work at 70mph and actually hit 23.1 on my way back at 70. It is pretty hilly but nothing too steep except one hill on my way to work I have to go up, it is pretty steep and maybe 1/16 mile long. I can go from 70 and hit 90 no problem in 5th and pressing the gas like halfway. So going up it the other way I have to take in 4th gear and I think I would barely accelerate up it if floored in 4th. But even on longer drives into the city around 60mph, I get home and see an average of between 20 and 21 and that's at 6000ft+ above sea level.
Think about it this way. Get a milkshake and suck it thru your straw.....see how long it takes to get a mouthful?....this is your stock filter. Definitely flows what it needs to but takes harder sucking to get it thru the straw. Now get a bigger straw(higher flow filter) suck just as hard and see how long it takes to get a mouthful. Or better yet try to see how much less suction it takes to fill up your mouth in the time it took you with the normal straw. I bet you won't have to suck as hard. Picture your mouth being the engine having to struggle more to pull the air thru, the straws are your filter and the milkshake is the air.
Think about it this way. Get a milkshake and suck it thru your straw.....see how long it takes to get a mouthful?....this is your stock filter. Definitely flows what it needs to but takes harder sucking to get it thru the straw. Now get a bigger straw(higher flow filter) suck just as hard and see how long it takes to get a mouthful. Or better yet try to see how much less suction it takes to fill up your mouth in the time it took you with the normal straw. I bet you won't have to suck as hard. Picture your mouth being the engine having to struggle more to pull the air thru, the straws are your filter and the milkshake is the air.
One point your missing, the OEM air filter isn't limiting the air flow into the engine. On the flow numbers I posted, with the OEM filter flow numbers, it isn't restrictive at all, so your straw analogy doesn't work. With CAFE standards, auto manufacturers design intake systems to be as efficient as possible.
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From: In the fast lane from LA to Tokyo...
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From: CO
One point your missing, the OEM air filter isn't limiting the air flow into the engine. On the flow numbers I posted, with the OEM filter flow numbers, it isn't restrictive at all, so your straw analogy doesn't work. With CAFE standards, auto manufacturers design intake systems to be as efficient as possible.
Like I said I understand the numbers part but if that is actually the case then there is no point at all to a higher flow filter, or exhaust, or doing the GOTTS mod because the stock setup allows ample flow.
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From: Durham, NC
I understand what you are saying but, it still makes it easier by being less restrictive. Many people have experienced more mpgs with aftermarket filters whether they are oiled or dry. Point is when it has to work less to get that air it needs, it is more efficient. So he's it does work with the straw analogy because a normal straw works just fine.....but a bigger one takes less work because it is able to move more milkshake whether you need more or not. Many people have experienced more mpgs with just a higher flow filter. And if your theory is correct, then the GOTTS mod has no benefits either....because that is making the inlet tube bigger to allow more air to be able to be pulled in. Also the stock exhaust works just fine...but a higher flow one allows more to be pushed thru...
Like I said I understand the numbers part but if that is actually the case then there is no point at all to a higher flow filter, or exhaust, or doing the GOTTS mod because the stock setup allows ample flow.
Like I said I understand the numbers part but if that is actually the case then there is no point at all to a higher flow filter, or exhaust, or doing the GOTTS mod because the stock setup allows ample flow.
The way the MAF, and O2 sensors in closed loop / PCM work, if you actually got more air flow, more fuel will be used, which will decrease MPG, not increase MPG.
Take a look at the diameter of the opening of the throttle body, and then look at the area of the air filter, and you will see even removing the air filter all together won't give you any more air flow.
Last edited by Takeda; May 20, 2013 at 10:54 AM.
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From: Under the flightpath of old ORD 22R
You will want to talk to a tuner that is well versed in your engine for the final word on this topic.
The 3v 5.4L ( 2006 with a build date of 1/06 ), the Gotts mod, using Autotap data logging, got an increase of 6% in specific RPM ranges.
It was not linear over the whole range, and did not have this rate of increase at the higher RPMs.
Same engine with a S&B intake got 10%+ flow rate at the MAFS ( tune adjusted ) over the Gotts mod, and had an increase over the whole RPM range.
This is from testing a 3v 5.4L engine with street driving, with Autotap, nothing subjective about it.
If the Gotts mod can increase the MAFS rate by 6% at certain ranges, that shows the stock setup cannot outflow the engine, when using a '06 3v 5.4L engine.
Talk to a tuner that does this for a living, not someone like myself, as the data logging on my truck ( with the setup I have ) might not be applicable to your truck.
If you have a eco boost, 5.0 or 6.2 L engine, you will get different results ( it is a different engine ).
Don't take the advice of people that use some "calculation" that is not a tuner for a living. Tuners put the modifications to the test with data logging, dyno runs and 1/4 ETs, not with a calculator only.
I know with the S&B intake, I picked up an avg 0.5 MPG over the Gotts mod.
- If the engine can deliver the same HP / TQ at a lower RPM, that will impact MPG.
If you use a fixed RPM range, the fuel consumption will be increased, but it is not taking into account what is going to the ground power wise.
Again, best to ask this of a tuner, someone that knows what the change will mean to your engine.
The 3v 5.4L ( 2006 with a build date of 1/06 ), the Gotts mod, using Autotap data logging, got an increase of 6% in specific RPM ranges.
It was not linear over the whole range, and did not have this rate of increase at the higher RPMs.
Same engine with a S&B intake got 10%+ flow rate at the MAFS ( tune adjusted ) over the Gotts mod, and had an increase over the whole RPM range.
This is from testing a 3v 5.4L engine with street driving, with Autotap, nothing subjective about it.
If the Gotts mod can increase the MAFS rate by 6% at certain ranges, that shows the stock setup cannot outflow the engine, when using a '06 3v 5.4L engine.
Talk to a tuner that does this for a living, not someone like myself, as the data logging on my truck ( with the setup I have ) might not be applicable to your truck.
If you have a eco boost, 5.0 or 6.2 L engine, you will get different results ( it is a different engine ).
Don't take the advice of people that use some "calculation" that is not a tuner for a living. Tuners put the modifications to the test with data logging, dyno runs and 1/4 ETs, not with a calculator only.
I know with the S&B intake, I picked up an avg 0.5 MPG over the Gotts mod.
- If the engine can deliver the same HP / TQ at a lower RPM, that will impact MPG.
If you use a fixed RPM range, the fuel consumption will be increased, but it is not taking into account what is going to the ground power wise.
Again, best to ask this of a tuner, someone that knows what the change will mean to your engine.
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From: CO
The way the MAF, and O2 sensors in closed loop / PCM work, if you actually got more air flow, more fuel will be used, which will decrease MPG, not increase MPG.
Take a look at the diameter of the opening of the throttle body, and then look at the area of the air filter, and you will see even removing the air filter all together won't give you any more air flow.
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From: Under the flightpath of old ORD 22R
Yes I see your point. But again...if its getting more air and adding more fuel....which creates more power, then you don't have to be on the gas pedal as hard because it is running more efficiently so you end up using less gas. Otherwise when the maf and o2 sensors adjust for that, if it adds more power than you would be accelerating. ...<snip>....
This is where the system uses the DMAP for calibration, ignoring the closed loop feedback.
- EPA does not track WOT numbers.
The 09+ could be different.
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From: CO
My scangaugeII drops pretty quickly at WOT lol. Least ive seen with it floored it 5.5mpgs. I have it set on instant and average. My truck is rated 20hwy and I am getting about 21.5-22mpgs on average. I have heard the 4.2 goes to open loop at 2500+ rpms too, according to my scangauge, mine is above 3000. Don't know how accurate it is bit I'm guessing its pretty accurate on most things.
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Senior Member
Joined: Dec 2011
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From: Durham, NC
My scangaugeII drops pretty quickly at WOT lol. Least ive seen with it floored it 5.5mpgs. I have it set on instant and average. My truck is rated 20hwy and I am getting about 21.5-22mpgs on average. I have heard the 4.2 goes to open loop at 2500+ rpms too, according to my scangauge, mine is above 3000. Don't know how accurate it is bit I'm guessing its pretty accurate on most things.
Open loop is used during engine warm up, and when the PCM detects the WOT signal, which comes from the TPS. The engine doesn't go into open loop at a specific RPM. In open loop, the AFR is determined from the fuel tables, and signals from MAF, and temp sensors. The engine will also stay in open loop (Limp Home Mode) with certain ERROR CODES.
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Joined: Jul 2002
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From: Statesville, NC
I recently put a AFE dry flow in my daughters Accord. we have seen a slight increase in mileage, but not enough to be worth while. Not having to replace it is the main reason I bought it. I am running a Volant CAI system with their dry filter on my Expd and am very hppy with it.
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From: Iowa
I have a very inexpensive way to do a 'pre-test'.
Drive a known path, stock air cleaner. Record mileage, observe performance. Or if you have the ability to record 0-60 times, etc... do that.
Remove element and repeat same path without ANY element installed. Maybe interstate with cruise would be most consistent. The improvement you see without an element in place represents the best case you would see with ANY element used, no matter design or style.
I know some of you are shuddering, but trust me, you aren't going to suck enough contamination during this test to harm your engine.
Anyway, this test will tell you what 'best case scenario' is, and if you aren't seeing gains, you won't see gains after you've shelled out the money.
Drive a known path, stock air cleaner. Record mileage, observe performance. Or if you have the ability to record 0-60 times, etc... do that.
Remove element and repeat same path without ANY element installed. Maybe interstate with cruise would be most consistent. The improvement you see without an element in place represents the best case you would see with ANY element used, no matter design or style.
I know some of you are shuddering, but trust me, you aren't going to suck enough contamination during this test to harm your engine.
Anyway, this test will tell you what 'best case scenario' is, and if you aren't seeing gains, you won't see gains after you've shelled out the money.
Senior Member
Joined: Aug 2008
Posts: 1,553
Likes: 1
From: CO
I recently put a AFE dry flow in my daughters Accord. we have seen a slight increase in mileage, but not enough to be worth while. Not having to replace it is the main reason I bought it. I am running a Volant CAI system with their dry filter on my Expd and am very hppy with it.