Please share experiences with BPP/K&N air filters

[lebikerboy]

Have a look at the following link where all types of filters were tested...

Filtration Testing for Amsoil, K&N, Napa, Jackson Racing, Baldwin, and Mazda air filters on a Miata

[SmartDigger]

Oil life plays a big part of the Ring job theory. One goes hand in hand with the other

[Smart_Dude]

Originally Posted by lebikerboy

Have a look at the following link where all types of filters were tested...

Filtration Testing for Amsoil, K&N, Napa, Jackson Racing, Baldwin, and Mazda air filters on a Miata

Although this page has been around for awhile, the tests are fairly conclusive and based upon systematic sampling. Results notwithstanding, it’s really a good example of sound scientific technique. Unfortunately (as the author implies) the testing was completed primarily in a part of Washington that is inherently 'clean'. Would be interesting to review the same testing in a ‘harsher’ environment, like inland So. Cal., the Southwest or Midwest during the summer months.

Million mile claims – made by the filter maker, no less – aside, the author’s concluding statement is… well… common sense (and I quote)…

“Really, it is up to each individual to decide. The poorer flowing filters, remove more particles, and the better flowing filters remove less particles. If you think about it, that conclusion passes any and all common sense tests, so it is not surprising.”

And I agree with him. It’s your ride… your car… your ‘investment’. Load what you want in it. For me, I’ll stick with paper filters.

Cheers,
Jeff

[Smart_Dude]

Originally Posted by NeWave

Then you better tell it to the one fellow who put a K&N drop-in in his truck when it was fairly new, broke the KN million mile warranty.. original trans and engine. Kept it very well maintained. They gave him a new truck...
The video is on their website...

Warranty:
ENGINE PROTECTION LIMITED WARRANTY
Unlike many companies, our warranty for O/E replacement air filters and intake systems does extend beyond the replacement of a defective K&N part. For the original purchaser of the product, our warranty covers any engine damage or related costs incurred as a direct result of the use of a properly installed and maintained K&N O/E replacement air filter or intake system on the specific vehicle for which the product was designed to be used by K&N. This includes reasonable vehicle repair costs, sensor replacements, car rental fees or other incidental expenses directly related to an engine problem caused by the failure of a K&N product. Furthermore, we warrant that using our product will not result in a vehicle warranty denial. K&N will not be responsible for any indirect, consequential, special, contingent, or other damages not listed above.

Referring to the following K&N news article…
Christmas Comes Early for Million Mile Truck Driver Carl Judice
At the time of the million miles (2006), the 1998 truck was 8 years old. Assuming the truck was delivered with 0 miles on the odometer and exactly 8 years later hit 1,000,000, the truck was driven an average of 125,000 miles per year (1,000,000/8). This means the truck averaged 2,403 miles per week (125,000/52). Or 342 miles a day (125,000/365)… every day… 365 days a year… for 8 years.

Folks, that means this pick-up truck - not a commercial long-distance hauler - was on the road 342 miles a day for 2,920 straight days (365*8). That includes all holidays, birthdays, Sundays, all types of weather, good health, sickness, auto maintenance, etc. Assuming a very generous average speed of 55 MPH, this truck is being driven over 6 hours every day (342/55)… for 2,920 straight days. Any slower average speed (more probable) and the daily driven time just gets longer. For reference, there’s only 24 hours in a day. Another way to look at this is that the truck lived 1/4 of its entire life at an average speed of 55 MPH. That's pretty amazing... too good to be true.

Further assuming a gas mileage of 15 MPG (rather generous for a late 90’s vintage truck), Mr. Judice is tanking up at least once a day. So add another 15 minutes to the average daily driving time. Does Mr. Judice ever do anything other than drive his truck? (Presumably, the truck is driven by multiple people. But you get the point.) Does this really make logical sense?!?

BTW, in order to keep the truck in even reasonable running condition, Mr. Judice is performing an engine oil change every other week (4,794 miles)… for 8 years. This is additional time (presumably) Mr. Judice is associated with his truck and this does *not* take into account maintenance time for tires, other fluid changes, brake maintenance, etc. Even assuming nothing broke on the truck requiring repairs, the fluid/periodic maintenance would add time to the truck’s ‘daily life’.

As a reference point, the small 2.4 liter Mercedes diesel engine is arguably considered to be one of the most durable and reliable engines on Earth. It is not uncommon for owners of the 240D to hit 1,000,000 miles. Here’s a real example…
'81 Mercedes with 1 million miles still drives well | ajc.com
But look at the age of the vehicle (1981) as compared to the date of the article (05/28/2008). Let’s see… that’s 27 years. A little more realistic at a mere 37,037 miles per year, or an average of 101 miles per day. And more and more of this age vehicle is hitting 1,000,000 miles; not 8-year old vehicles, regardless of the brand of air filter! Do a simple Google search (Mercedes + million miles). There's a bunch of 'em - all 70's or early 80's.

Finally, let's exercise some of our little grey cells... If this truck really hit 1,000,000 ‘engine on’, driving miles in 8 years, don’t you think GM would be far more interested in the publicity than K&N?!? I must have missed that story. I’m sorry, but this tall tale just doesn’t add up.

Lesson learned: Don't believe everything you read, especially wild claims that just seem 'too good to be true'. Food for thought. Peace.

Cheers,
Jeff

[fortow]

My comments regarding K&N filters are almost identical to Smart Dude's. Decades ago when I raced bikes off road we used oiled gauze and foam filters. They were designed for that purpose because they would not clog when covered with dust/dirt nor would they break apart when wet, and they would still flow air when wet. They were used on engines that were exposed to mud and water and which were rebuilt frequently. That is a suitable application for these oiled filters but they are a poor alternative for road use.
For awhile I did use a K&N replacement filter on my road bike as well. A coating of dust quickly became noticed inside the plenum chamber which is supposed to be clean since that is where air has passed through the filter. This is not a situation that was desirable for a road going machine.

The following website is also a good and reliable comparison of air filters. K&N does not fair well.
ISO 5011 Duramax Air Filter Test Report
K&N has been accused of misleading claims. They produce a well made product which is desirable for certain applications. Unfortunately they have been targeting gullible enthusiast markets and road going vehicles lately for which these products are not entirely appropriate. If you want to be deceived you will be. If you feel that their claims are justified and enjoy using these products then that is your business - but at least you should be aware of the issues involved in their use.