+1.2mpg isn't anything to sniff at, and the improved acceleration, as I said, is a welcome addition in CBus. I'm sold

 

I would say an almost 4% fuel economy gain is extremely significant for a changed air filter, especially if you have more peak power, which begs the question -- why don't the automakers use these to begin with? Engineers will go to extreme lengths to get a 4% efficiency gain, so using an inferior air filter seems like a very low-hanging fruit.

 

Convenience and cost. What do you think the answer will be when the guy in the boardroom suggests using a filter that cost $15 bucks more (a guess) and has more maintenance. And some of these car companies produce 50,000 or more cars a week. Do that math.
That's one of the reasons why the aftermarket exists.

 

Not to mention that air-filter maintenence is a recurring LABOR cost (money for the dealer) and NOT a recurring PART cost (money for both the dealer and the manufacturer).
Potential liability for over-or-under oiling (the maintenence) would likely be a concern also.

 

Well, the general consensus among the racing guys is "It's the first mod we do," though they also strongly caution against over-oiling the filter, as it'll cause MAF (Mass Air Flow sensor) problems.

 

*** SCCCREEEEEEEEEEEEEECCCHHHH ***
That sound you hear is me slamming on the brakes after reading this: http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

 

I am not surprised by this test. I had an F-150 truck that I hauled horses with for 20 years, frequently on dirt roads. I ran a K&N filter for a few years, but stopped because the throttle body kept clogging with dust! The truck would start idling rough and progress to stalling frequently when stopped if I did not clean out the throttle body every 5 or 6 months when I used the K&N filter. A ridge of dust would accumulate around the throttle plates, blocking off more air than the EFI system could adjust for.

After I switched back to using Fram paper filters, I could go several years without having a rough idle from the dust build up. The Ford 5.0 V8 with EFI is prone to dust build up, but it normally takes 20 to 30K miles to show up, not 4 or 5K miles like I experienced with the K&N filter.

FYI, I did clean and oil the K&N filter a few times to see if it would help, despite the "50K before cleaning is needed" wording on the filter box...

PS - Interesting how well AC Delco's filter performed in that link!

 

Any performance benefits would be so minute, that you'll more than likely not feel it. It's called the "seat of the pants" test. Any power gains are possibly due to placebo effect.

The best indicator would be to test both filters either on a dyno, or a drag strip.

I believe the only benefit of a K&N is the ability to clean and reuse. You'll definitely save money over it's longevity. Personally, I'd rather not worry about cleaning and reoiling. I just buy the stock filter. I don't know if any tests have been done with Honda car filters, but their OEM motorcycle filters have proven to be superior to K&N.

If anyone is local within the Phoenix metro area, I have an accelerometer which tests 0-60, 1/4 mile times, and 60-0 braking. I'd be happy to meet up with you anywhere around here to test the K&N out. My accelerometer is accurate to within 1/100's of a second. Or, we could meet up at Speedworld Motorplex. Wednesday nights are $15 ($10 military), unlimited runs, run what you brung...