Please don't beat on me too much, but yes I tried to increase my MPG with a simple K&N airfilter and haven't made any progress.

I've read where SOME people were seeing fuel mileage increase with the K&N so I decided to give it the $40.00 try. I knew it was too good to be true, but had to try it.
Anyhow, 3 tanks into it and the first stank (13.27mpg-w/ some offroading in 4x4) 2nd looked good (15.56) & 3rd stunk (14.44) all manually calculated.

Ride- 04 CC FX4, 3.73 gears.

I plan on doing 2 more tanks and then switching back to a regular filter and running it for 5 tanks for comparison.
I run my mileage on every tank, but we've recently switched to the ethenol blend that wasn't supposed to be MPG friendly so I'm not sure about my old readings.
With a paper filter I consistently get mid 14's to low 15's.

My question is- Would pulling the ground on the battery for a few minutes "reset" my computer and get me anywhere (adjust for new airflow)? or is that just a wives (co-workers) tale?

Thx, Dave

 

You do not have to reset your computer. But you can if you want.

 

I bought the filter haven't put it on yet. Has anyone really seen a small increase in horsepower or gas mileage with the filter alone??

 

I'm not sure about anything obvious because I put mine in at around 10k and have around 45k on the truck now so I can't really tell you of an increase. But I do get around 18-19 hiway and 14-15 city in an '04, Screw,5.4L, 4x4 with 3.73 ls.

 

I put a series 77 intake with K&N filter on my truck (04 Screw, 3.73 LS) and noticed only a marginal difference in performance; mpg was almost unoticeable probably about a 1 mpg improvement but I did feel horsepower increased, especially when towing. From what I understand you won't get any considerable gains until you revamp your exhast system with high flow cat and muffler. In the end the cat back is the most restrictive part of the system so the gains of a filter cannot be measured until the cat back has been replaced.

I had my dealer reflash my computer about two months ago and realized another 2 mpg improvement, this is because a lot of the old 04's and even some 05's had different programing (timing, etc) and Ford has made some improvements - I don't think its related to the filter.

 

I think in a deisel is where you would see intake and exhuast make hugh increases. Or if you happen to slap a turbo on your truck. I know that K&N have a good rep on the hp and mpg increases, but I think you would only see them on the dyno. Even if you get 5 more hp, would you really feel it when you jump on the pedal? I think if the new intake was part of a whole new system, then they might add up to some good numbers. Perhaps intake, headers, no cat and a new high flow muffler, then you might see some change. I bought my K&N more for the fact I don't have to buy a new filter just recharge after a while.

 

I think I read before I got mine at K&N's website that you could see 3-5% increase or something to that effect so I used the minimum amount and thought perhaps I have around 309 hp now. I agree with buying the K&N to avoid having to buy paper filters every so often. The K&N pays for itself in no time if you think about it, and then some.

 

4x4150, believe ot or not I THINK I could feel a slightly quicker revving engine when zipping through traffic, nothing huge but enough to make me think I might have gotten somewhere with it.

 

I put one on my '04 SCrew 4X4 4.6L and didn't see much difference in the MPG or horsepower. Of course, I never dyno'd the motor to see either way. This reminds me - I have to look at mine and probably re-oil it 'cause it's been in for 20K and I drive to a lot of construction sites.

I waited too long to have the fule filter changed (27K vs 15K recommended) and I picked up 2 MPG after that.

 

Well thanks for all of the feedback, from everyone. If it makes it a little bit peppier than that works too.

 

The very minimal increase in MPG and/or performance is due to WWR (Wallet Weight Reduction).

 

I used to use K&N all the time in my Mustangs. They are good for a street only car. However, if you drive in dusty or off road conditions i would not use one. I have seen reports that the K&N's let a lot of dirt through.