Early K&N vs OEM Filter Results

[popennell]

Alright, I know there's ALWAYS a ton of debate/discussion around performance air filters, but I've got some results that I'd never have expected, so I thought you all might enjoy hearing about it.

I pulled out the OEM air filter and decided I didn't like it at all; it looked cheap, felt cheap, it's like an air intake tampon. I was displeased. I decided to buy a K&N filter from Amazon because it was about $10 cheaper than through my local parts store, even with next day air, so I jumped on it. I swapped out the filters, threw the OEM filter next to the spare tire for the inevitable 24 hour cleaning the K&N will need, and did some driving.

Here's the deal: I'm using stats from the last tank of gas; I've only burned part of the tank since the K&N filter, drove the same routes using the same driving style, the CC is not on. Here's what my early results are showing:

Tank average with OEM filter: 47 mpg.
Real-time fuel economy cruising (rough average): ~51 mpg

Current tank average with K&N filter: 51 mpg.
Real-time fuel economy cruising (rough average): ~65 mpg

It's still early in the tank, but I haven't gotten these numbers consistently out of this car during in town drives, so this is a major improvement. Once I'm further into the tank, I'll update this number.

[joecvt]

Just for grins.....after this tank is done, put the OEM back in just to make sure your MPG goes down again.....The reason I suggest this.....there may be other factors involved in your recent higher MPG

Warmer weather is always a positive towards higher MPG....
Driver getting more experince with achieving higher numbers may also be a factor.

I'm not saying the K&N is no good but like with any test or troubleshooting, you should be able to produce predictable results and if you don't try it, you will never know if other factors were involved.

JoeCVT = Just your average CVT owner

[popennell]

Originally Posted by joecvt

.....after this tank is done, put the OEM back in just to make sure your MPG goes down again.....

But of course! What kind of an experiment would this be if I didn't at least try to rule out possible variables?

[Cobb]

Interesting.... I am tempted to try cleaning mines or try a standard filter again.

I found with my super charged tacoma I was cleaning the red filter that turned black after 2 thousand miles of use always gave a bit more performance for a few weeks til it blacked up again. I could hit 15 vs 13 psi of boost too with a fresh cleaning.

[amcdonal86]

Why the heck do these K&N filter discussions pop up on every automotive forum known to man! Surely with a car as complex as the Insight, the air filter makes little difference! Heck, try running the car for one tank without an air filter at all! You should see better improvement versus the K&N, right?

[Cobb]

I wouldnt recommend removing the filter.

[popennell]

Originally Posted by amcdonal86

Why the heck do these K&N filter discussions pop up on every automotive forum known to man!

Automotive Forum. That's a major contributor to the problem. Automotive forums have a tendency to be infiltrated by tech-savvy motorheads who love nothing more than big block V8's stuffed under the hood of an El Camino or Catalina just to hear it roar and visit every gas station in town.

Those guys tend to be obsessed with performance parts, like the K&N filter. The reason the air filters come up so often is because they make them for virtually everything. Not many people will be looking for new headers for their Insight, but everyone replaces the air filter at some point...and that's the appeal: it's easily accessible and it's a part associated with better performance.

[cheesie]

as soon as i put the k&n on my I2 i started gettn more mpg
but never went back to the cheap tampon

[Hitech]

Classic placebo affect me thinks

Modern cars operate on a "closed loop" and as a result the air filter has zero affect on gas mileage, it can only affect top end HP when the air filter becomes the "throttle" restricting total air flow.

[amcdonal86]

I think we should break into these people's cars, replace their K&N filters with stock ones without telling them, and then come back on the forum. I bet you they will still be singing the praises of their increased gas mileage with the K&N filters... with a stock paper filter.