Truck Trend claims 10% more MPG with K&N in 2009 Ford F-150 after bogus road test

[blueflame]

The computer compensates with ecu, in non ecu you run too lean until you find a cotton cushion case to cover the pod.

Some engines may prefer a K&N theres no doubting. But on its own most dont. Unless you want a more race engine or like change a 30mph scooter to a 50mph scooter. I would always choose a high flow air filtration system to matched my larger intake manifold and less restrictive exhaust pipe.

But for ecomiling the family wagon I'll keep my torque curve lower with the standard air box.

Maybe faster drivers do benefit with certain high output vehicles.....

Depends on the manufactures configuration as to what a pod will do, usually the ecu just compensates.

[jamesqf]

Originally Posted by Frank Lee

I read the K&N "flows better" because the holes in it are bigger? Then I especially wouldn't want to use it there.

Just for a guess, maybe because with the K&N it's not the size of the holes, but that the dust particles get trapped in the sticky oil? At least that was what happened with the "wet" filters I used to deal with on logging & construction equipment, where oil would circulate and the dust would settle out in the bottom pan... (Sorry if my description isn't clear: it's been a couple of decades.)

[Christ]

Originally Posted by jamesqf

Just for a guess, maybe because with the K&N it's not the size of the holes, but that the dust particles get trapped in the sticky oil? At least that was what happened with the "wet" filters I used to deal with on logging & construction equipment, where oil would circulate and the dust would settle out in the bottom pan... (Sorry if my description isn't clear: it's been a couple of decades.)

I know exactly what you're talking about here, but I haven't seen an implementation of it in years.

The K&N surely is designed to catch particulate in the oil, and the oil expands the cotton gauze to close up the holes some. The problem is that when the size of the holes are measured, it's (ideally) done after the filter is "ready for service". So that would mean that even after the oil is placed on, and all tests are performed, the K&N filter still flows larger particles than the normal pleated paper filter does.

[Frank Lee]

My POV: I have plenty of stuff with oil bath/oiled foam air filters- old VWs, old B&S engines, somewhat newer B&S engines. They are all a pain in the arse with the seemingly constant service requirements.

And, IIRC, I read somewhere that they don't even filter as well. Seems hard to believe bubbling air up through a vat of oil wouldn't catch everything...

Newer equipment with paper elements = tap and/or blow out some dust occasionally. Hardly ever need to replace.

My cars must see unusually clean air duty as service intervals are long and replacement intervals nearly non-existant. My mowers and other small engined stuff do see lots of dust and whatnot but even then the only times I've had to replace paper elements was when they got gas soaked- they wouldn't flow after that.

[blueflame]

When I was younger I used to buy new paper filters every couple of years. What a waste of money looking back.

[Frank Lee]

Same here. Finally caught on.

[tasdrouille]

Originally Posted by Frank Lee

tap and/or blow out some dust occasionally. Hardly ever need to replace.

This is common practice in emerging countries. I actually have an SAE paper here where they tested various methods to clean and reuse OEM paper filters. The best way to do it is to tap it a couple times on a flat surface, then blow it from the clean side with compressed air. You should just be careful not to contaminate the clean side while doing so.

[Christ]

Originally Posted by tasdrouille

This is common practice in emerging countries. I actually have an SAE paper here where they tested various methods to clean and reuse OEM paper filters. The best way to do it is to tap it a couple times on a flat surface, then blow it from the clean side with compressed air. You should just be careful not to contaminate the clean side while doing so.

It's ironic that we have to look to "up and coming" countries to find ideas on how to live properly and recycle/reuse, and stop wasting so much.

[MetroMPG]

Originally Posted by jamesqf

Now if it did increase fuel economy, that'd be a plus, but I haven't seen anything like an honest test (other than that link from Darrin, which I think was too short for accuracy)

Hey, I won't dispute that.

I've learned a lot in the last few years about what constitutes good testing, and that particular one (and more than a couple of other early ones I did) doesn't qualify. A-B-A or bust, just for starters.

So where's the real-world test? Put one in a vehicle, drive a couple of thousand miles, or at least a tank or two, and see if mpg improves.

That's the whole point! Neither of those things constitute a valid test. Too many variables.

What bothered me most of all was that they deemed a dyno test the best way to evaluate the intake & filter's effect on power production (hey - why not do "on road" timed acceleration or top speed runs for that?), and then decided basically uncontrolled on road testing was adequate for fuel economy evaluation. They could have done both on the dyno!

[Christ]

Originally Posted by MetroMPG

They should have done both on the dyno!

Thereifixedit!

Of course, a top speed run is far too variable for checking HP increases... what if top speed occurs in an area of the RPM range outside the HP increase? Well, that would show a 'nil' result, right?

Acceleration, also too variable. I mean, you've got shift times, humidity, heat index, tire selection, driver mishaps, etc... Jeebus... seems like any kind of "on-road" testing is just WAY TOO VARIABLE, EH?

I hope someone other than me sees this and understands exactly just what went on here.