K&N Drop-in filter

TacoJoe11

Well-Known Member
A couple months ago replaced my stock air filter with a K&N. I have a coworker who swears by K&N, so I figured I'd give it a try. Hoping to see maybe a little gain in mpg, not drastic.

I didn't have high expectations, but this was the reverse of what I thought would happen. I got worse gas mileage! I even disconnected the battery to reset the computer to compensate for the increased airflow. With the stock filter was running about 18 -19 mpg, which I was ok with, but now getting below 17. Feels like it was gradually getting worse. I ran with it for a couple of months in hopes for it to equalize.

For the time being I put back in the stock replacement filter and going to see if their is any improvement or at least back to where it was.

Anybody else use K&N's or experience the same problem? Did I do something wrong? As of now I have no faith in K&N replacement filters.
 
I run the K&N drop in filters in every thing I own and have never experienced a loss of gas milage. Maybe contact K&N themselves and see what they have to say about your experience.
 
Usually K&Ns are over oiled from the factory. I say clean your MAF now that you ran it.

The only benefit of an aftermarket filter is that you can wash it. Paper does a better job at actually filtering the air since aftermarket filters have less dense filter media to allow that "extra flow." More dirt gets past the filter.
 
Never had any noticeable dirk get past mine, oil either. That's just my experience with 11 of them so far.
 
I bet very few people will notice more dirt but what's the point of buying something that offers no benefits besides being able to wash it but it takes several years to overcome the cost of the filter in the first place.
 
Constant air flow was my primary objective, and I accomplished it. I'm very happy with them. They filter air in an entirely different way than your standard paper filter, the dirt itself acts as the filter media, that and the oil. That's why you can go for longer periods without cleaning them were you'd changed out several paper filters during the same time interval. There's where you save. I like the fact that there isn't that period of time where the paper filter is getting dirty but not dirty enough to change yet your air flow is starting to diminish. You don't have that with a K&N. Just because a K&N is dirty does not mean it isn't working, unlike paper. You don't clean a K&N because it's dirty, that's when it's working at its best, as long as it's wet, no dry spots.
 
But as far as making up the cost it takes about 3+ years to make up the cost if you follow the maintenance schedule of the air filter. Just because a paper filter looks dirty doesn't mean it's clogged. I'll do the math later...
 
Figure on replacing the paper filter as soon as air restriction starts, not just when recommend.
All in all it's mute anyway. I'll still use them because I like the convenience and I think they are better. I'll take my experience over your math, sorry. Each to his own. Some people replace perfectly good working bulbs with what they think is a better bulb. I don't, but that's me. K&N air filters have served me well on my Muscle cars, my ATV's, and my 4x4's. I live in the country on a dust ranch and I swear by them.
If'n you don't like em, don't use em.
 
Lol. Just stating facts.

I used them before. No issues on my TT RX7 with K&N but I still wouldn't get another.
 
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I wouldn't use any oil based filters in anything that has a sensor that could get fouled because of over oiling. A dry base filter is the way to go.
Also, paper or not surface area on the filter is everything. Doesn't matter if your talking about your car or motorcycle or even the hot air furnace in your house or heck even the two nostrils on your head. The larger the area the less restriction you'll have and the better you'll breathe.
Most air filters used for the automotive industry have a rating of particles of dirt down to around 5 micron and capture 98 percent of the dirt. The only filter that clams and has proven that it can do better is made by Donaldson which it can capture 99.9 percent dirt with the same air flow and it's NOT paper.
Also, if your worried about keeping you motor clean get a better oil filter. Stock oil filters clean dirt particles down to around 40 micron. High performance oil filters, which have better flow as well, get down around 5. I'll also add the Donaldson makes that one as well. Go figure.
If you want you can add to that list of taking the in tank fuel filter out and putting a inline one that would also do a better job which could also be replaced on a regular basis instead of getting clogged and not knowing what the heck is wrong.
 
Thanks maybe I will contact K&N to see what they have to say...maybe i'll get a refund.
Probably not a bad idea to clean my MAF sensor, that could explain the worse mileage with my fuel to air mixture being off.
 
Pulled the MAF sensor and it was pretty dirty. Cleaned it up and made a couple trips with the truck today. Seems to be running a lot better, rpm's arent erratic like they were before. Hopefully the mpg's get back to normal after a couple of weeks.
 
I would clean and re oil the filter. When applying the oil just put enough to take the white away but not too much to where it is deep red or dripping.
 
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I just have the dry filter in right now, it's a purlator. Not sure if I want to put the K&N back in.
 
TacoJoe, any updates on your filter? Before i read this thread i already ordered my K&N drop-in. I am hoping to increase HP when hauling loads. My truck was already a gas guzzler as we do alot of family outings in it. Now with my 33's im sure ive dropped 2-3mpg highway. Iʻll be testing my mpg next with stock filter before i replace. But my primary concern is power.
 
Whipper, the head meaning the entire intake system? If so i opted to that route with either the K&N or Trd. But want to keep it near stock too. Ive seen on youtube the power gains on the intake system but i dont drive like that at all. Im just hoping more air will flow internally when i need it. Especially when i do a Mauna Kea trip that ascends up to 13,000 ft and the air is thin.
 
K&N hot air intake gives a negative 5 horsepower gain. Real cold air intakes may give 5 to 10 hp with the most from the URD intake. If you are looking for real gains skip the intake and get the blower for $3800 because that's the only change you will really feel. It will also help at higher altitudes.
 
So my K&N air filter arrived and gonna install it soon. What concerns should i have with all this talk about MAF sensors needing to be cleaned because of the pre-oiled filter. Is there a mileage log i need to be aware of to clean this sensor upon installing? Ive read other Taco owners never having issues while others have.
 
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