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I want to report out on the fuel usage now that I put a K & N replacement air filter (this is NOT the CAI referred to in other posts) on my 2011 EQUINOX 2.4 L FWD. First of all, years ago I put the same type of filter on my 02 Impala 3.4L and it increased my MPG by 1.0 (3.2%). I expected the same results on my NOX, but go better. With the replacement filter, my actual MPG (not DIC) increased by 2.11 (7.0%)-from 30.23 to 32.34. All of my calculations were done in 1,450-1,550 mile increments to reduce any pump to pump variation, using the same gas station and as much as possible similar driving conditions (about 98% of my driving is my daily work commute-flat country roads-few stop signs & lights). I installed the filter at 9,500 miles on the odometer, an easy five minute job (the OEM filter still looked in great shape).
Another interesting thing I noticed is the change in error when comparing the actual MPG to the DIC.
With the OEM filter, the DIC calculated 0.73 MPG (2.4%) lower than actual. With the replacement filter, the DIC calculated 1.34 MPG (4.1%) lower than actual. I don't know why, but it looks like the computer is not learning that less gas is being consumed.
Bottom line-at the current $3.50/gallon gas price, it will take about 7,000 miles of driving for me to break even-everything after that is a gas saving bonus (A WIX or Delco is almost half the cost of what I paid for the K & N).

OEM Filter K & N Replacement Filter

ACTUAL MPG 30.23 32.34

DIC MPG 29.5 31.0
 

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JA said:
I want to report out on the fuel usage now that I put a K & N replacement air filter (this is NOT the CAI referred to in other posts) on my 2011 EQUINOX 2.4 L FWD. First of all, years ago I put the same type of filter on my 02 Impala 3.4L and it increased my MPG by 1.0 (3.2%). I expected the same results on my NOX, but go better. With the replacement filter, my actual MPG (not DIC) increased by 2.11 (7.0%)-from 30.23 to 32.34. All of my calculations were done in 1,450-1,550 mile increments to reduce any pump to pump variation, using the same gas station and as much as possible similar driving conditions (about 98% of my driving is my daily work commute-flat country roads-few stop signs & lights). I installed the filter at 9,500 miles on the odometer, an easy five minute job (the OEM filter still looked in great shape).
Another interesting thing I noticed is the change in error when comparing the actual MPG to the DIC.
With the OEM filter, the DIC calculated 0.73 MPG (2.4%) lower than actual. With the replacement filter, the DIC calculated 1.34 MPG (4.1%) lower than actual. I don't know why, but it looks like the computer is not learning that less gas is being consumed.
Bottom line-at the current $3.50/gallon gas price, it will take about 7,000 miles of driving for me to break even-everything after that is a gas saving bonus (A WIX or Delco is almost half the cost of what I paid for the K & N).

OEM Filter K & N Replacement Filter

ACTUAL MPG 30.23 32.34

DIC MPG 29.5 31.0
will be snatching one of these up very soon...as i do nothing but highway miles with mine!!
 

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Ive always used kn filters in my cars. It causes less drag on acceleration. If u put the original filter back in u can definately feel the difference in acceleration
 

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JA I find your info fascinating. One question though. What is the mileage of your Nox as the gas mileage improves almost every fill up to about 25000 with this engine. I was just wondering if any of this effect is affecting the results -- Beyond that K&N has always bee a superior filter and actually I am not surprised.
Finally - I hear of a CAI for the Nox..... Is there a good, well made one for our car??
 

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I don't dispute the MPG claims. My concern is: at what price?

K&N and other similar filters allow more airflow for increased performance and MPG but with that increased airflow comes an increase in the amount of particulates (ie: dirt) that it allows into the engine. Even a properly oiled filter still allows more dirt into the engine than a factory filter.

Has anyone done a oil analysis with the factory filter and then another after switching to a K&N? I would be interested in the results.

Personally I don't understand why GM wouldn't just put a reusable filter in from the factory to gain a little more MPG if there wasn't a valid reason. Yeah they cost more initially but for the price of the filter compared to the MPG gain it would be a very inexpensive way for GM to increase the overall MPG for a vehicle. I have to believe that the risk outweighs the gain from their perspective. Just wondering. Any thoughts?
 

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filter choice also affects intake manifold vacuum which sometimes needs to be in a specfic range for all of the emissions things to work properly, plus GM has to back that warranty so they want as little dirt and dust getting in there. I would think they could require a specification on filtration for warranty purposes. The easier flow doesnt put in any more air, it just makes it easier for the piston to pull air with less vacuum, so it will rev easier. Same thing with opening up the exhaust, it will rev easier with less backpressure working against the piston on the exhaust stroke. Seeing as the combustion of another cylinder has to do the work for the exhaust stroke of another cylinder pushing against backpressure in the exhaust system.

I would like to put the K&N pipe on there and use an Amsoil Ea nanofiber filter, far superior.
 

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Black Granite LTZ said:
I don't dispute the MPG claims. My concern is: at what price?

K&N and other similar filters allow more airflow for increased performance and MPG but with that increased airflow comes an increase in the amount of particulates (ie: dirt) that it allows into the engine. Even a properly oiled filter still allows more dirt into the engine than a factory filter.

Has anyone done a oil analysis with the factory filter and then another after switching to a K&N? I would be interested in the results.

Personally I don't understand why GM wouldn't just put a reusable filter in from the factory to gain a little more MPG if there wasn't a valid reason. Yeah they cost more initially but for the price of the filter compared to the MPG gain it would be a very inexpensive way for GM to increase the overall MPG for a vehicle. I have to believe that the risk outweighs the gain from their perspective. Just wondering. Any thoughts?
Very good thinking - and well said. I agree - if GM could get and extra 1-2 MPG for under $100 (with no downside), then they would be all over it.
 

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Discussion Starter #8
For Rick Tinley Park-the MPG reading with the stock filter is 9,500 miles on the odometer, & 11,000 miles with the K & N. I have not noticed any difference in MPG from the time the Equinox was new through 9,500 miles(with stock filter)-so I can't even say from winter to early summer temperature is affecting my results like I would expect it to.

JA

OEM Filter K & N Replacement Filter

ACTUAL MPG 30.23 32.34

DIC MPG 29.5 31.0

MILEAGE 9,500 miles 11,000 miles
 
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