I ve used K&N air filters on my last 2 F150's 02 and 06, it seemed to solve the choke point I had with the the 2 trucks when you kicked em in the @#$ getting on the highway etc. I havent noticed the 09 doing this when accelerating to pass or getting on the highway. Is it worth the money for the 09 or just leave it stock? What your opinion?

 

After looking at some test results I saw on the net some years ago, I would never use a K&N. The test showed the amount of dirt the filter, straight out of the box, allowed to pass through. Much worse with the K&N than with a paper filter.
And that doesn't include problems caused by after cleaning the filter if it is over oiled.

 

I guess shame on me I was one for never read any test data!!!! I guess I was doing more harm than good to the motors when using them. Any alternatives to stock filters or just keep the stock/

 

A buddy of mine with a 5.7 put one in. It dirtied up the MAF so bad his truck wouldn't get out of it's own way. User error? Maybe. I know I won't be using an oiled filter with MAFs.

 

I've been perfectly happy with my K&N dropin for 86,000 miles. Saves money on filter replacement. Truck does not use oil and never had an MAF problem. You just need to be able to follow directions when reoiling. I clean it about evert 20,000 miles.

 

I looked at the air intake system yesterday as I checked the oil level. There's plenty of baffles occupying a lot of space but I suppose it's there for a purpose (making sure laminar air flow occurs into the manifold). The oil saturated air filters are not for my liking. It's too bad Ford doesn't provide performance parts for it's trucks like GM does for Chevy and GMC. Overall, I'm reluctant to change the OEM air intake system at this point.

 

I looked at K&N test data as well AND suggestions on here. I went with an Amsoil EaA filter. I know the nanofiber technology is the latest and it filters better than oiled gauze and standard paper. Plus it is cheaper now and in the long run. No brainer for me.

 

I had the K&N for about 85,000 and finally made the mod to enlarge the intake openning as shown in the How To section. I have about 1500 miles since doing that. Since I have a custom tune, the extra air is noticeable.

 

I've read the negative K&N results with thier cold air intakes, but not with their drop in factory replacment. A key difference.

I use a K&N as I can clean em and reuse. Overall much cheaper. Never had a prblem over last 15 years.

 

I ran K&N until AEM hit the market in 2001. Never looked back, now over 190,xxx and not single issue.

 

I use K&N on Carb'd vehicles. No question. They flow more, and with my carb'd motors, I care more about HP/TQ than I do with motor longevity.


on a EFI motor, no way in hell I'd use a K&N. I did once way back when on a 1995 Mustang....up until I found dirt on the motor side of the filter.

The K&N filter just doesn't do a good enough job of filtering. It's just a filter with lots of big holes...too much grit/crap gets through.



And then you have to worry about the oil on the filter messing with the MAF and IAT (if present)




highly recommend a good paper filter

 

I had considered buying a K&N until I read some reviews like this. I decided to go with an Airaid CAI. So far it seems to work fine.

 

It depends on the operating conditions. Clean city air maybe. Rural or off road, not so much. It gives the dealer ammo to deny power train claims. K&N's have to e oiled to work. Too much oil and it gets on the MAF hot wire element and burns it up. This is real common on GM. GM techs have a bulletin they give every customer with a K&N stating Gm will not warranty any MAF issues. Also more air means more dirt unless you drastically increase the size of the filter. If you trade in every 100k it probably doesn't matter. If you live on a farm and want to go 300k and ten years you will want to stay stock. Donaldson is a good mil spec filter company. I have also used AFE 7 layer stuff on diesels.

 

I do a lot of highway driving and where I work there is nothing but dust and dirt. After the comments I guess i will stick with stock filter for now till I do some research. Thanks all

 

i bought my airaid CAI when i was at 32k and im now at 61k and its ran SO much stronger...the bigger throttle body helps too :-)