K&N or AFE?

What does rpm have to do with your air cleaner? Your transmission and rear end control the rpm/mph.

There is no reason your rpm would be higher with one filter over another unless somehow your torque converter isn't locking up with one for some reason?

 

lol

 

does either filter help with mpg. should i go with the entire cold air system or just a filter for better mpg?

 

You won't get better mpg with a different air filter, or cold air system.

 

I like Airraid.

 

I realize this thread is old as dirt, but K&N is not difficult to clean or oil IMHO. The whole process takes 5 minutes (plus time to dry before oiling). I've no complaints with K&N and I'm on my 4th vehicle with K&N now and still using the same recharging kit.

 

I've always run KN in everything. The box says clean every 100,000 miles and that build up in the filter helps filtration. I know dusty/offroad conditions warrant cleaning more often, but over cleaning is bad for the filter. Did I read it wrong?

 

I don't think you want to clean it too often. My approach is clean it religously - which is to say, only when I think of it. That works out to about twice a year.

 

AFE definitely

 

even tho i am an amsoil dealer, i use afe. tired of the oil mess and problems which can result therefrom.

 

would there be a difference in just putting the afe filter in oem box vs putting a afe filter on a CAI? im new to this so dont yell at me


p.s. can someone provide a link to buy such items please and thanks

 

i just bought the are and put it in the stock box. google are air filter and you'll get bunch of online stores selling them. i don't remember the name of the place i bought from. but it was 55 bucks shipped. by the way, according to my ultra gauge, my mileage did increase. when a motor doesn't have to work as hard to pull air in, up goes efficiency.

 

Your ultra gauge isn't precise enough to tell one way or the other, but strict laboratory testing using precise repeatable test loops say they don't increase mpg.

http://www.fueleconomy.gov/feg/pdfs/Air_Filter_Effects_02_26_2009.pdf

Pretty simply, the filter is not the restriction that is causing the motor to "work hard to pull air in" as you say. Under anything but wide open throttle, the throttle plate restricts the intake, that is how a gas motor is controlled. At any cruising speed the throttle is only slightly open, this causes the restriction and it doesn't matter if the air filter is more or less restrictive as the throttle plate is by far the biggest restriction. With no filter the throttle plate may open slightly less for the same speed, with a nearly clogged filter the throttle plate opens slightly more for the same speed but the mpg stays the same and the total restriction stays the same.

A restricted air filter may produce slightly less HP at wide open throttle and at 4-6000 rpm, but at part throttle it doesn't matter.

But throttle response, that another story.

 

I just added an old used KN cone filter to the end of my oem intake arm. No significant gains over drop in amsoil filter. Just better throttle response on take off.

 

I guess it depends on your maintenance desires since the AFE is winning the poll. I've used K&Ns on my bikes and trucks for many years and never minded cleaning them. The manufacturer's data alone is enough to make me stick with K&N. The purpose IS to increase air flow after all.

AFE PRO DRY AIR FILTER = 416 CFM
K&N = 706.3 CFM

 

If the engine can't use it, it doesn't matter.

CFM = CID X RPM X VE / 3456 (3456 = 12" X 12" X 12" X 2 revs per CID)
CFM = 242CI X 5500RPM X 90% / 3456 = 346 < 416 < 706. Even 100% volumetric efficiency is less than 416 cfm

You aren't increasing air flow just because the filter can flow more.

 

Under perfect conditions where zero dirt exists that is true (even though that math is way beyond anything I want to figure out), but the fact is there will always be dirt in the filter. Given the same amount of crud build-up in both filters, the less restrictive filter will give better performance. Again, individual maintenance preference matters more, as they are both great filters. I'll stick with the K&N. They are cheaper anyway.

 

The point is the engine doesn't need a high flow filter if it doesn't flow that much air anyway. You can't get better performance if the filter can outflow the engine.

 

Point taken.

My point is dirt in the filter will restrict airflow. If not, why do you ever have to change/clean it? The less restrictive filter will remain the less restrictive with the same amount of dirt packed into it. If you are saying there is no point at which a clogged filter restricts airflow then you are dreadfully wrong. By your logic one should never have to change the factory filter.

Anyway, find a paper element filter with factory specs that is cleanable/reusable that is cheaper than both and I'm in there like swimwear.

Otherwise: 1x $54 K&N > 1x $57 AER > Many x $24 Fram filters over the lifetime of the truck.

 

After reading the link that I provided on post 77 I have decided to go 60k miles interval before changing the filter for me. They found no change in MPG but reduction (7%) power with filters that are 2-3 times more clogged than a filter with 30k of use. A dirty filter actually filters more, which is a good thing. No argument a very dirty filter will reduce peak power, but not with your typical 30K interval.

With my 2.7L I don't care if I lose a few HP at 5500rpm, I don't see that engine speed anyway. I picked up 3 oem filters at the dealer for $14.99 each, that's 240k for $45 including the original.