I was searching Ebay for a K&N Filter for my 2000 5.4L 4X4 Expedition. I noticed alot of used filters. What's your opinions on buying used ones that are not used over 10,000 miles? It looks like the majority of them said they were on vehicles under 10,000 miles. Im looking to help boost my gas mileage.

 

Use synthetic oil this will give you more mpg.For an air filter I would use a 2 stage foam filter. The k&n filters seem to seperate more and more after each cleaning.Check out this site www.amsoil.com

 

People are finding out that the K&N doesn't give any increase in performance or MPG, and they let more dirt pass into the engine...
This is why there are so many used ones for sale..........

 

Never had a dirt problem with my K&N's The one in my Mustang has been in theresince it had 9,000 miles on it. It has 156,000 now. I have never had to clean my MAF. Looked at it the other day. I have a ram air scoop that sit's about 2" off of the ground so it is very acceptable to dirt. I have cleaned leave, cig. butts and everything else out of the filter housing before the filter, but the intake tract is as clean as it was when new.
The only problem with K&N's is when the user over oils them after cleaning. If the directions are followed, it will give you a lifetime of service.
I have had no adverse effects out of the one in my 01 F150 either.

Oh and my Mustang did pick up 1/10th in the 1/8th mile just by changing the filter. I used to drag race it every week!!!!
Jimmy

 

My opinion? Why would anybody buy a used air filter?

This did give me an idea though. Maybe there's a fools market for my used oil filters.

 

stick with a new paper filter, and keep the K&N oil out of your maf sensor.

Trust me on this one, there is no worthwhile power gains with this filter on a stock truck.