Another duke Mileage Question !

[Tom S.]

Duke do you see any fuel mileage advantage to the K&N or other type high flow air filters ? I have a friend that puts them on everything he has and swears by them.I told him in my opinion if that technology was so great the Manufacturers would be using it! What is your opinion on these and what else can you do to get the best mileage? I am not talking vets here but the wifes car!I keep the oil and all filters changed, the air pressure up, what else?Tom

[Ken A.]

Re: Another duke Mileage Question !

I can't speak for Duke, but GM has voided warranty claims on cars with "oiled" filters. Seems too much oil clogs up the MAF 7& throws all kinds of weird diagnostic codes.

[Terry M.]

Re: Another duke Mileage Question !

I routinely have my oil analyzed. I changed both Caprices to K&N air filters and the silicon -- an indicator of dirt -- climbed dramatically. Anyone want a couple of K&N air filters for 1994-1996 Caprice/Impala?

[Bob S.]

Re: Another duke Mileage Question !

I routinely have my oil analyzed. I changed both Caprices to K&N air filters and the silicon -- an indicator of dirt -- climbed dramatically. Anyone want a couple of K&N air filters for 1994-1996 Caprice/Impala?

I find this very interesting.......about 15 years ago I was considering putting a K&N on an new performance car. After reviewing the product info they supplied, I refuse to put a K&N filter on any of my vehicles.

As they say, you can manipulate statistics to show (or hide) whatever you want. K&N's data showed that the number of particles of a given size allowed to pass increased from 2% to 3% compared to a stock filter; a seemingly minor increase until you consider that's really a 50% increase!

Terry, it looks like you've reached the same conclusion I did! (BTW: part of my 25+ year career in automotive engineering was spent working for a "household name" brand of filters...)

Regards,
Bob S.

[Clem Z.]

Re: Another duke Mileage Question !

I routinely have my oil analyzed. I changed both Caprices to K&N air filters and the silicon -- an indicator of dirt -- climbed dramatically. Anyone want a couple of K&N air filters for 1994-1996 Caprice/Impala?

they let enought dirt thru to polish the impellers on duramax diesel turbochargers that GM tells the dealer to void the warranty on any duramax with polished impellers even if the K&N was not on when the truck was brought in for warranty work. with the new 5 year/100,000 mile warranty GM is getting tough and they can also tell if you had the computer reprogramed for more HP even if it has had the stock GM program put back in.

[Terry M.]

Re: Another duke Mileage Question !

I see over on CF about the computer -- the guys with "tunes" are having fits.

[Clem Z.]

Re: Another duke Mileage Question !

I see over on CF about the computer -- the guys with "tunes" are having fits.

when i posted this over there it got attention. "the PCM detects and RECORDS the last 10 upload and download sequence.
And yes, it can be seen by a technician with a Tech 2."

[Duke W.]

Re: Another duke Mileage Question !

I absolutely postively admonish all to NOT use K&N filters or similar filters other than the OE reproduction foam filter - for judging only.

For road use install a quality name brand cellulose filter.

Oil wetted filters do a poor job of particle filtration, and they do not outflow or out power conventional cellulose filters

A few years ago Hot Rod Magazine of all sources did a filter test of 14" x 3" air filters which is a common size. Several name brand OE replacement filters and a same sized K&N were tested both on a flow bench and on an engine on a dyno.

The K&N DID NOT flow the best of those tested, nor did it make the most power, but the results were pretty close. The test can easily be found on Hot Rod's web site using their search tool.

The bottom line is that the incessant hype you see and hear about K&N air filters is BS like so much of the other hype on aftermarket products.

They are grossly overpriced junk!

Duke

[Robert K.]

Re: Another duke Mileage Question !

Duke,

I just wish that you would tell us what you think instead of "beating around the bush" so much!!

Take care,

[Tom S.]

Re: Another duke Mileage Question !

Thanks for the input! Some very good info here. The Dura-max would not run right on K&N when they first came out in 01. My buddy put one in his and could not get it to run right at all and took it out. The other guy has one in his Dura-max and I sent him a note on this! As far as putting them on vettes my 08 has all the power I want stock, it needs no help in my opinion..My 88 could use the help but I just took out the original, after 13k it looked great!! I am going to leave well enough alone! Thanks guy's for the input and helping me win an argument!! Tom

[John H.]

Re: Another duke Mileage Question !

People seem to forget that diesels are unthrottled and ingest max air volume at all times - that's HARD on air filters, and demands a GOOD one with LOTS of effective filtration surface that won't clog easily. A K&N will die LOTS faster on a diesel than on a gas engine.

At Chrysler we routinely tested competitive air cleaner submissions, and K&N's always were least effective in terms of filtration (particle size), and deteriorated rapidly. Why do people buy them? The triumph of marketing hype ($$) over facts.