K&N vs. MPG?

[Dr_Snooz]

Hi all,
Has anyone else noticed a significant drop in gas mileage (~4 mpg) after installing a replacement K&N filter (not a CAI or short ram or anything)? I've noticed it on two Accords now, an '89 and a '93. Any thoughts?

Thanks!
Paul

[Vanilla Sky]

I would assume it would work the other way, if anything. It reduces pumping losses that are exaggerated by clogged filters, and to a lesser extent, paper filters.

[labeledsk8r]

yeah i have only seen gains in mpg after going K&N... never a drop

[Vanilla Sky]

When was your last full tune-up?

[Dr_Snooz]

Last tune up was a couple months ago. I run only Chevron 91 octane. Two injectors are new. It's definitely the filter. ???

[MessyHonda]

i got a gain when i did mine but i also ran seafoam with the old filter.

[AccordB20A]

when i put a pod filter on my car used more gas. so from what i think a more free flowing filter will make your gas mileage worse, but it should improve power and response from the engine

[Dr_Snooz]

That's true. It's got loads more power now. :-)

[Blkblurr]

when i put a pod filter on my car used more gas. so from what i think a more free flowing filter will make your gas mileage worse, but it should improve power and response from the engine

Your right on the money.

[DBMaster]

Actually, using 91 octane will generally reduce your fuel economy compared to 87. There are more than enough good explanations online if you are interested.

Did you get a K&N sticker with your filter? I hear that's good for another 5 HP.

[Hauntd ca3]

the drop in inlet restriction caused by the k and n will fool the ecu in to thinkin the engine is under more load than with the standard filter.
the ecu would have been programed with the oem filter set up and therefore will recognise
the lower vacum signal caused by the k an n filter as an increase in load.
it will think its driving up a gentle slope when it should be thinkin its on the flat.
the only way round this is a re written chip in the ecu to suit the diff map signals its now getting

[Blkblurr]

It actually just sees more air flow and add the fuel to keep the ratio the same. I just put it in simple terms

[Hauntd ca3]

It actually just sees more air flow and add the fuel to keep the ratio the same. I just put it in simple terms

sorry, just the mechanic comin out but yeah thats pretty much it

[Oldblueaccord]

Over oiled filter?


wp

[clark_486]

What about the carb'ed intakes. does the more air = more fuel used?

[Oldblueaccord]

Clark

in short yes....... but the problem is carbs dont really adjust for airflow. you have to rejet the carb everytime where fuel injection has some adjustment.


And just to add I got 27.3mpg city with a KN filter cone.


wp