To All:

I'm NOT here to do a commercial for K & N Engineering. Just so happens that I've used their products 30+ years now...beginning on my Honda motorcycles.

For many years, I have used a K & N air filter in my trusty '86 Accord, and I just ordered one for my '02 Accord. WHY?

Don't get me wrong; factory air filters, for the most part, do an "adequate" job and are "cost effective," assuming you change them at reasonable intervals. Really depends on where you live and what kind of driving you do.

Main problem with most OEM air filters is their substandard composition. The element is usually pleated paper and/or foam. These materials will typically contaminate (clog) quickly, especially if you drive in dusty/high-smog environments. When they clog up, you WILL typically notice a significant drop in MPG and overall engine performance. After a "standard" air filter is contaminated, upon WOT (Wide Open Throttle), and typically having no wire/plastic mesh structural reinforcement, the pleats and/or foam can collapse together. Result? The F/A (fuel-air) ratio is all out of kilter, and your engine runs like CRAP. You GET what you PAY for. Growing rather tired of all this, I soon switched to K & N.

OEM air filters? Use them ONCE, then throw them away. K & N air filter? Drive (say) 20-to-50K miles, wash and re-oil it, and you're good to go again. To wit, and to date, I've never found a reason/excuse to throw a K & N air filter away.

Am I persuaded by K & N's "added performance" claims? Do I care if their filter actually delivers an "X-percent" BHP and torque increase? Of course not. I am interested ONLY in maximizing engine PROTECTION....and being "cost effective."

My local Honda dealer hits me for $18.14, for an OEM air filter, which MIGHT (and the operative term is PERHAPS) be good for 30K miles. Given reasonable care, a K & N filter is (purportedly) good for 10 years or one million miles.

For those who own a 1998-2002 Accord V6, interested in the K & N filter element, the P/N is: 33-2133. I shall soon pick mine up from AutoZone. I forced them into an Internet price match of $36.30.

Robert Warden
BSME (retired)

**********************************
1986 Accord Hatchback, LX-i, 5-speed, Misty Beige Metallic over Silky Red (216K miles)
VIN: 1HGBA5348GA167648
2002 Accord Coupe, LX, V6, Satin Silver over Charcoal (81K miles)
VIN: 1HGCG224X2A011655

Instead of cleaning a conventional filter at 15k I replace it instead. I also use the Fram filters instead of oem. Below is a thread about air filters you may find interesting esp when an engine gets dusted. :paranoid:

http://www.driveaccord.net/forums/showthread.php?t=7419&highlight=air+filter&page=2

One other thing I do is at around 7500 I rotate the air filter because it seems the lower half of the filter is much dirtier than the top half. If you look into the pleats in good light.

SatinSilver:

I enjoyed reading your thread. I see quite a bit of controversy and debate about air filtration systems. But I find it healthy discussion, and I like that. It makes me THINK.

I inspect my air filters once a year, regardless of mileage. If necessary, I will clean the filter, and I will clean the housing and induction tubing. Being a (retired) engineer, I am fanatical about cleanliness; dirt IS a natural enemy of any engine! I drive approximately 5,000 miles per year now. The filters in both my cars can NOT be rotated because of the angular shape (in my '02) and because of the filter indexing tabs (on both cars). I wish it were otherwise.

(Editor's Note: During my 24-year career as a manufacturing engineer, I spent some seven (7) years working in a telephone production facility. My principle experience is with stamping presses (metal base plates, housings, brackets, and so forth). On many occasions, I (unfortunately) found it necessary to "chew out" a department foreman who refused to properly maintain the AIR FILTER unit on, for example, a Walsh 38-ton press. Reason(s): When the filters clogged, machine efficiency was reduced by some 50-to-75+ percent. Result: A component backlog, necessitating (expensive) overtime schedules. Then when TRASH destroyed the "O"-ring piston seals and/or galled the pistons, the press DIED. End result: The entire production process ground to a screeching halt. Now, I have an entire factory management team screaming at me...because ONE person (foolishly) chose the wrong place...to cut his overhead costs.)

Aside from myself, those I know who use a conventional air filter element often (gently) blow it out with compressed air, and may use a soft-bristle brush attachment on a shop vacuum to clean it. This is especially true if the particular vehicle is fitted with a large filter element that is otherwise expensive to replace. Quick example given: A 2008 Toyota Tundra fitted with 5.7 L V8. The Fram version (CA10343) will cost you $28.39. Our local Toyota dealer charges around $35 for an OEM replacement. My next door neighbor cringed when he saw both prices; he was expecting to pay about $10-$15. (And YES, he purchased the Fram element. He is very "cost conscious"..as in cheap!)

In the thread, I notice that FredSVT severely condemns the use of K & N filters. And that is fine, bearing the particular application in mind. Operationally, diesel engines are quite different from four-cycle engines. Typically fitted with a "blower" (supercharger) and extremely high compression, a thoroughly-clean air supply is an imperative, not a choice. One of my "buds" who turns wrenches on European cars (Volvo, BMW, and Mercedes) has rebuilt/replaced several M-B "Turbo Diesels" due primarily to poor filtration maintenance. And as Fred points out, the owners weren't too happy with the bill.

As previously stated, I have had good experiences with K & N air filters. But you can't just drop it in and forget about it forever. You DO have to periodically wash it and re-oil it.

Can I suppose that everyone would love a vehicle that would easily go 250,000 miles with absolutely no maintenance? Sure. While that makes for great "chalkboard theory," life simply does not work that way...in the real world. Most everything, particularly MACHINES, must be maintained. And the basic equation always boils down to "cost-benefit analysis." "Value engineering." Always so prone to set issues up as a "linear programming" equation, to myself, it's just "maximization of positive outcomes utilizing the minimum amount of necessary resources."

Ergo, ONE K & N air filter element plus ONE "cleaning/re-charging" kit equals (in my case) about $46. Expected service life: ~Ten years/one million miles. (Realistically, 100,000 miles.) Expected cost of ten years of OEM Honda or aftermarket air filters: ~$200+ (I have not factored in for inflation). Expected service result: The same (or better) at approximately one-fifth (1/5th) the cost, vis-a-vis the K & N air filter element.

Robert Warden
BSME (retired)

**********************************
1986 Accord Hatchback, LX-i, 5-speed, Misty Beige Metallic over Silky Red (216K miles)
VIN: 1HGBA5348GA167648
2002 Accord Coupe, LX, V6, Satin Silver over Charcoal (81K miles)
VIN: 1HGCG224X2A011655

Ergo, ONE K & N air filter element plus ONE "cleaning/re-charging" kit equals (in my case) about $46. Expected service life: ~Ten years/one million miles. (Realistically, 100,000 miles.) Expected cost of ten years of OEM Honda or aftermarket air filters: ~$200+ (I have not factored in for inflation). Expected service result: The same (or better) at approximately one-fifth (1/5th) the cost, vis-a-vis the K & N air filter element.

I have to disagree with your cost comparison. An aftermarket filter costs $10. Buy 5 of them over ten years and we're only at $50 (vs. $46 for your K&N).

I haven't looked into the K&N enough to know if it's better or not, but I always fall back on this - if the auto manufacturers could include an OEM K&N air filter for a few bucks more (they would get a huge volume discount from K&N) that boosted MPG + HP and saved maint costs (since it's "permanent"), why wouldn't they???

Of course, I'm an EE, so WTH do I know about air flow? :D

Cajun:

You make a very fair point. However, I will counter by saying the basic concern always goes back to..M-O-N-E-Y. I'll bet you've done some "MTM" studies, "value engineering," and (otherwise) enough tedious cost analyses to make you cross-eyed.

Sadly, this now TENDS to be the principal function of many engineers. I got sick of it. After 24 years calculating fractions of one cent, I burned out. My abiding concerns are A) Component SAFETY. And B), Correct FUNCTIONALITY of the component/system.

I am NOT interested in pleasing some JERK in Accounting/Finance who is trying to "impress" his/her boss...for a raise and/or promotion.

About 30 years ago, I vividly recall doing machine "cycle" costs on a new Artos wire stripper/terminator. The Accounting Dept. required six-digit precision. (YES, I said SIX digits, to the right of the decimal point.) That was about as much fun as watching paint dry. Assuming regular maintenance, expected MTBF was ~10,000 machine hours (or ~4.8 years). The department foreman "cheaped out," subtracting the (optional) factory warranty out of his annual budget. Most (unfortunately) pleased with my numbers, the Accounting Dept. encouraged him to do so. The machine (tongue-and-insertion plate) broke, after about 4,233 hours of use. And he ended up paying about HALF of the machine's price...to repair it. Gotta LOVE STUPID PEOPLE!

I've sure had my fill of the guys (and gals) in Accounting and Finance. And the Legal Department. However, while cost concerns TEND to be the deciding factor, that is NOT always the case. There are other factors that must be taken into consideration, in the creation and production of any mechanical/electrical system. And there are always inventory concerns, respective to component "holding costs" and "shelf life." A LOT of stuff to THINK about. Correct?

Ergo, Honda likely MAY be unable to "partner" with an aftermarket supplier such as K & N Engineering. Probable Reasons: A) Component price too high. B) Supplier cannot meet required schedule on deliverables. C) HMC Engineering is (yet) unconvinced of a technological advantage/performance improvement. D) Some combination of thereof.

I should add that many suppliers do not want to get caught up in a "monopsonistic" relationship with any given concern. Let me be SPECIFIC: Most companies do NOT want to engage in "one-horse" contractual situations. Example given: I would NOT want to be a supplier (contractually) "tied" to a GM or a Chrysler. With both of them in severe crisis, my company (likely also) would be going down the tubes!

In business, one must be very CAREFUL with whom they "get in bed" with. Example given: Rubber Maid, once one of the most admired companies in America, tied their fate to Wal*Mart. Failing to meet Wal*Mart cost-reduction dictum, Wal*Mart brutally punished them by reducing shelf space. Now, Rubber Maid is a "case study" for the MBA students.

Okay, Sir. I've STILL got you beaten by ~$4.00. And totally subtracting out of all their advertising hyperbole, a company such as K & N could not remain in business for so long...if they were peddling JUNK.

In ONE SENSE, neither Honda nor any other manufacturer has an incentive to incorporate a system component that lasts (virtually) forever. WHY? I want to sell MORE parts, NOT less! I have to produce MORE dealership (service department) profits! And I have to keep the (dealership) technicians BUSY, else they might starve to death! You get the picture...

Please bear in mind that the fully-synthetic lubricants I use in both my cars were once regarded as "specious." Now, they have become the "de facto" standard in many vehicles!

Allow me to HOPE (and pray) that better air filtration is NEXT on the horizon!

Robert Warden
BSME (retired)

**********************************
1986 Accord Hatchback, LX-i, 5-speed, Misty Beige Metallic over Silky Red (216K miles)
VIN: 1HGBA5348GA167648
2002 Accord Coupe, LX, V6, Satin Silver over Charcoal (81K miles)
VIN: 1HGCG224X2A011655

The Honda OEM filters are very good. Purolator also makes good aftermarket replacements.

I put a new filter in at 127k miles in August, a Purolator, and as of 142k miles, it still looks very good. The one that came out was an OEM Honda and it looked downright awful.

A/C filters are commonly forgotten on the 6th gen Accord. I've seen many where they were NEVER changed. Mine was original when I bought it in 08,with a stamp of 5/99 on the side of it. Changing that filter made a night and day difference in howmy car smelt. I wish I had pictures of it.

Instead of cleaning a conventional filter at 15k I replace it instead. I also use the Fram filters instead of oem. Below is a thread about air filters you may find interesting esp when an engine gets dusted. :paranoid:

http://www.driveaccord.net/forums/showthread.php?t=7419&highlight=air+filter&page=2

One other thing I do is at around 7500 I rotate the air filter because it seems the lower half of the filter is much dirtier than the top half. If you look into the pleats in good light.

Don't know if anyone has mentioned this, but don't rotate the filter. The bottom half looks dirtier because it has contaminants closer to the surface. When you flip the filter it makes it more likely for those contaminants to be sucked into the engine.

A/C filters are commonly forgotten on the 6th gen Accord. I've seen many where they were NEVER changed. Mine was original when I bought it in 08,with a stamp of 5/99 on the side of it. Changing that filter made a night and day difference in howmy car smelt. I wish I had pictures of it.


A/c filter? As in cabin air filter?

I bought my car with 141,000 miles on it. I imagine the filter was never changed, and the picture shows it! I noticed the air smelled like a gravel road when I wasn't driving on one, so I figured I'd better change it. :D I'm sure you can tell the new filter is on the left and the old on the right.

http://img.photobucket.com/albums/v715/alaina615/011108_21271.jpg

To All:

I purchased my 2002 Accord in late September of 2008. Very FIRST thing I did was change ALL the fluids and filters.

Fluids and filters (IMO) are the very LIFE of any machine!

Changing the CABIN filters on a Gen Six Accord (as many of you well know) is...or CAN be...rather much an unpleasant chore. You have to disassemble about half of the right-hand (passenger's) side of the dashboard.

My car was "Honda Certified," back in 2006. This rating means NOTHING...as some ham-fisted IDIOT broke off the left-hand screw "boss" where the glove box mounts into the dashboard. Said idiot ALSO broke the lower dash "rail," where the glove box (metal)reinforcement/mounting plate attaches. Needless to say, I was NOT too happy about these findings. At least the JERK left me with the broken part...to reattach!

Said JERK ALSO broke a screw bracket on the left-hand side of the filler panel attaching directly below the glove box. I'd like to REVOKE his "ASE" rating, since it cost me about $45 to replace it. Gosh, I could do BETTER...with my EYES CLOSED!!!

Most dashboards are now a composite, elastomer "substrate." (In simple terms, they are hard ABS, covered with a layer of polyurethane foam, with a PVC outer "skin.")

However, in the case of damage, they DO respond very well to a two-step epoxy or a fiberglass resin. Hard ABS (nee, Acrylonitrile butadiene styrene) is rather "stringy" in composition, and can be treated/serviced just like conventional fiberglass.

My '86 Accord does not have the benefit of "cabin filters" in its HVAC system. Having rebuilt it not long ago, I typically leave the dash setting on "Recirculate," hence leaving the door (in the blower unit) CLOSED, to prevent entry of dirt, leaves, pollen, and etc.

I would NEVER reuse the "cabin" filters on a 1998- 2002. Or any other Honda, so equipped. And be sure to GENTLY use a shop vacuum, fitted with a thin "snout," to clean out the evaporator unit, prior to installing your new cabin filters.

Robert Warden
BSME (retired)

**********************************
1986 Accord Hatchback, LX-i, 5-speed, Misty Beige Metallic over Silky Red (216K miles)
VIN: 1HGBA5348GA167648
2002 Accord Coupe, LX, V6, Satin Silver over Charcoal (81K miles)
VIN: 1HGCG224X2A011655

[Hi Robert,

On any fuel injected car, the air filter being dirty will not reduce fuel economy.

If the filter becomes clogged, it becomes the throttle, and power is reduced. The car will not run any "richer" as the feedback system won't allow it.
The car will run progressively slower as the lack of air is compensated by a reduction in fuel.

On a MAF sensor equipped car it's immediately "seen" by the MAF sensor as a reduction in air flow, the car is only fueled to the amount of air entering.

On a MAP (speed density) car like many Hondas, the lack of air, and resultant lower manifold vacuum is seen by the MAP sensor, some extra fuel is added, but the air/fuel or O2 sensors will see this and the PCM will compensate by pulling fuel out, once the compensation reaches a certain point, the PCM will code a P0172 for rich mixture, but usually by that time the car's operator notices a severe reduction in power.

I wish I could figure out how to post a dyno study done with an engine MAF equipped that had the air filter at full flow, 25%, 50% and 75% percent restricted. The engine actually had lower fuel consumption at 75% restriction, any higher and the performance of the engine is seriously reduced at higher load/speed.

A carbureted engine will get seriously piggy on dirty air filters, as the vacuum in the intake travels up the carb body to the restriction (filter) and fuel is pulled like crazy out of the bowl.

I myself am perfectly happy with stock air filters, changed at 30k intervals. I've never had one clog, but I don't drive on dirt.

I'd never use a K&N or any other filter of that type. Especially on any engine used in the dirt. I've seen more than several dozen 7.3 powerstroke diesels destroyed by them as the air demand of these engines just pulls the dirt right through them and you can see the mud in the intake system, which gets boosted by the turbo and wipes out cylinder 5, then 7, and so on until there's no compression. By that time there's no compressor blades left on the turbos.

On a low load gas motor, you may have some extra margin there, but i've seen many cars with them have major dirt pulled into the intake systems.

Sorry if I posted in duplicate. Kinda distracted at the moment.

Said idiot ALSO broke the lower dash "rail," where the glove box (metal)reinforcement/mounting plate attaches. Needless to say, I was NOT too happy about these findings. At least the JERK left me with the broken part...to reattach!


I have a good guess as to why "said idiot" broke your metal mounting plate. On mine the left screw spins, but won't back out. I figured out that I could remove the right screw and rotate the plate/bar down with the left screw still attached. It gave me just enough room to move to the next step in the process without bending/breaking anything. In your case the tech may have figured his quickest option was to break off the plate. :furious:

Don't know if anyone has mentioned this, but don't rotate the filter. The bottom half looks dirtier because it has contaminants closer to the surface. When you flip the filter it makes it more likely for those contaminants to be sucked into the engine.

I don't flip it over since the filter wouldn't fit right and like you said the dirt would be sucked into the engine. Raise up filter and turn it 180 degrees.

FredSVT:

You astutely point out the DETAILS I (lamentably) neglected, respective to EFI versus carbureted engines. I have the facts. However, please excuse me for presenting them so poorly!

Maybe I need to forget everything I learned about carburetors. They belong in the Smithsonian Institute...on display for your kids and grandchildren to see! Most of the techs coming out of the trade schools nowadays are not even trained about carburetion, even those who are ASE certified! In terms of technology, oft times the past belongs in the past. Quick example given: Manual typewriters. We no longer have even ONE store that sells/repairs an old Royal or Underwood!

ONE exception: The small shops that work on OPE (Outdoor Power Equipment). Both my string trimmer and leaf blower are equipped with a Poulan two-stroke engine, fitted with a CARBURETOR. That is likely to change, as the "Greenies" are pushing to eliminate more "greenhouse" emissions. Speculation as to what a Weed Eater will COST...after it's fitted with ECU-controlled EFI?

On a carbureted engine, a clogged air filter WILL tend to affect fuel economy since, as you say, the available manifold pressure is sucking more gas out of the float bowl(s). And what you typically see is a lot of black exhaust...due to said over-rich mixture. You'll probably be "wet-fouling" plugs. And the engine will generally run like crap.

Exactly as you say, an EFI engine, when the air filter becomes severely clogged, the ECU, vis-a-vis signals from the MAP sensor and the 02 sensor, will basically match the available air with a corresponding amount of fuel. This will adversely affect POWER and overall performance, NOT mpg.

That said, I shall add that (via personal experience on my '86) a malfunctioning 02 sensor will adversely affect fuel economy. And, a malfunctioning manifold IAT (Intake Air Temperature) sensor will tend to produce an erratic idling issue.

BACK to air filtering:

Well, Fred. It's like this, Sir: I have used a K&N air filter in my '86 going on 10 years now. Still in great shape, I inspect and clean it once a year. And, as I said in another post, I ordered and (just yesterday) installed a K&N air filter for my '02. I can NOT tell you that either car actually PERFORMS any better than with the stock filter. What I CAN tell you is both cars run just fine. PERHAPS I'm getting better protection. And perhaps I wasted my money. Time will tell.

Cajun:

At your local Honda dealer, you can likely get a tech to print out the instruction set to remove and replace the cabin filters (from the Honda Techline). The procedure for "R&R" on the cabin filters is NOT sufficiently explicit. To a degree, it is NOT very clear about the SEQUENCE of removing the parts. IMO, what an inexperienced tech will do is attempt to remove the glovebox before they remove the lower bracketry. Hence, the glove box does not have sufficient "wiggle room" to pull it out. Result? They end up breaking one or both of the screw "bosses" that attach the glove box to the dash, upper left and right, respectively. They may also damage the lower part of the dash; I'm talking about the thin, plastic rail, just in front of the lower glove box mounting bar (metal bracket).

In short, they tend to start at the top and work their way down. To me, that is BACKWARDS. I suggest removing everything at the BOTTOM, working your way up. (And vice-versa, to reinstall everything.)

Bear in mind that the tech is doing "commercial" work. He is there to earn a living and turn a profit for the dealer. But me? I desire assembly line (or restoration) perfection. While I'm an engineer, held to the exact, high-precision standards of my profession, the tech is usually a certified tradesman, doing the best he can, with what resources are available to him. This obviously creates a conflict in the way of expected outcomes. While I want a flawless result, he just wants to get done and get paid. No need for further elaboration; you get my point.

While I'm on my "soap box," let me add that there is an enormous demand for automotive technicians. Although many of them make excellent money, the "burn out" rate is still quite high. WHY? Modern automobiles are extremely complex devices and extremely difficult to work on. I grew up in a time when automobiles were fairly simple, even primative. But today? They have computer-controlled everything. EFI, ignition, front/side air bags, four-wheel ABS, GPS navigation, backup cameras, and even automatic parallel parking systems...just to name a fraction of incorporated, modern technology. I am utterly AMAZED the techs do as well as they do, given the severe demands placed upon them.

I used to "get by" pretty well with simple, basic hand tools. Nowadays, a dealership tech needs a seriously-equipped Snap-On (or Mac) tool chest to be reasonably effective and efficient. Typical investment cost: $100,000.00 Just blows my (middle-age, old-fashioned) mind!

If all the college presidents DIED today, what would be the net effect upon the economy? Essentially ZERO. However, if all the automotive technicians DIED today, what would be the net effect upon the economy? Almost complete paralysis.

This is WHY I love and respect my "Gear Head" buddies so dearly. THEY literally make the world WORK!

I have not had a PE (Professional Engineer) license for many years now. Musing through a (current) sample test not long ago, I quickly realized I couldn't pass it to save my life. My young, "Gear Head" buddies would stand a far better chance. And most of them never attended college. Why? Many of the old, mechanical systems I learned have been replaced by electronic systems (specifically, semiconductors). I grew up in the day of a "Kettering" style distributor, with points, condensor, and coil. Now we have "Hall-effect" MOSFET systems, utilizing a crank-angle sensor. Makes me feel STUPID.

In almost every technical manual I've ever seen/used, I invariably find where a "communication breakdown" occurred between the engineer who designed the part/system...and the technical writer trying to explain it to everyone else. But it's really difficult to distill "perfect" information onto a printed page. Also "time intensive" and "labor intensive" as in...expensive!

Robert Warden
BSME (retired)

**********************************
1986 Accord Hatchback, LX-i, 5-speed, Misty Beige Metallic over Silky Red (216K miles)
VIN: 1HGBA5348GA167648
2002 Accord Coupe, LX, V6, Satin Silver over Charcoal (81K miles)
VIN: 1HGCG224X2A011655

One way to tell how well the air filter is doing its job is to have a uoa done. Then you'll know if too much dirt is being sent into the engine.

Theres alot of misinformation on bitog but some of it is interesting nevertheless. Below is a link discussing air filtration.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1232955&nt=5&fpart=1

Whew..now I don't have 666 posts anymore. :D

Whew..now I don't have 666 posts anymore. :D

Funny. I assumed my autotragic would burst into flames as I crossed 66,666 miles a few weeks ago. :banana:

SatinSilver:

Thank You for your posted link. YOU make me THINK! I LIKE THAT!!!

Speculation as to precisely WHAT is the effect of the OIL in a K & N air filter....upon the MAP (Manifold Absolute Pressure) sensor?

Perhaps, just to entertain myself, I should get on the phone...and play some "what if" scenarios...and "mind games" with K & N tech reps? THAT sounds like great FUN!

And I MIGHT even LEARN something NEW!

Hyperbole sure goes a LONG way, when you want to sell something. Great MARKETING makes for great MONEY!

"A sucker is born, everyday. And NEVER give a sucker an even break!" (Phineas T. Barnum, the famous circus showman)

Robert Warden
BSME (retired)

**********************************
1986 Accord Hatchback, LX-i, 5-speed, Misty Beige Metallic over Silky Red (216K miles)
VIN: 1HGBA5348GA167648
2002 Accord Coupe, LX, V6, Satin Silver over Charcoal (81K miles)
VIN: 1HGCG224X2A011655

I have to disagree with your cost comparison. An aftermarket filter costs $10. Buy 5 of them over ten years and we're only at $50 (vs. $46 for your K&N).

Reciprocally, I must disagree with your (somewhat) flawed cost analysis. We need to look at everything in terms of "constant dollars," over time. Based upon historical data, we must (reasonably) assume an annual inflation rate.

Being conservative, I will assume a CPI of two (2) percent. Please bear in mind that forecasting some ten (10) years out provides a very flimsy, very weak computational result. Too many variables can change in the equation.

The equation used is: TV = P(1+R), exponentially raised to "N" number of time periods. (As well as money, this also works well to calculate expansion of a bacteria culture.)

Ergo, TV (terminal value) of $10(1.02) exponentiated ONCE equals $10.20. But you have calculated for me replacing the air filter every SECOND year.

The ESTIMATED final cost of using an aftermarket air filter is $55.27. If I include for year ten (10), then it becomes $67.46.

Check all the Math yourself; my HP calculator never fails me!

But BACK to "Square One." I'm NOT so much interested in the PRICE. What is the intrinsic BENEFIT, in terms of performance and PROTECTION, to my engine, utilizing a K&N air filter element?

THAT is the REAL QUESTION!

Robert Warden
BSME (retired)

**********************************
1986 Accord Hatchback, LX-i, 5-speed, Misty Beige Metallic over Silky Red (216K miles)
VIN: 1HGBA5348GA167648
2002 Accord Coupe, LX, V6, Satin Silver over Charcoal (81K miles)
VIN: 1HGCG224X2A011655

Reciprocally, I must disagree with your (somewhat) flawed cost analysis. We need to look at everything in terms of "constant dollars," over time. Based upon historical data, we must (reasonably) assume an annual inflation rate.

Being conservative, I will assume a CPI of two (2) percent. Please bear in mind that forecasting some ten (10) years out provides a very flimsy, very weak computational result. Too many variables can change in the equation.

The equation used is: TV = P(1+R), exponentially raised to "N" number of time periods. (As well as money, this also works well to calculate expansion of a bacteria culture.)

Ergo, TV (terminal value) of $10(1.02) exponentiated ONCE equals $10.20. But you have calculated for me replacing the air filter every SECOND year.

The ESTIMATED final cost of using an aftermarket air filter is $55.27. If I include for year ten (10), then it becomes $67.46.

Check all the Math yourself; my HP calculator never fails me!

But BACK to "Square One." I'm NOT so much interested in the PRICE. What is the intrinsic BENEFIT, in terms of performance and PROTECTION, to my engine, utilizing a K&N air filter element?

THAT is the REAL QUESTION!

Robert Warden
BSME (retired)

**********************************
1986 Accord Hatchback, LX-i, 5-speed, Misty Beige Metallic over Silky Red (216K miles)
VIN: 1HGBA5348GA167648
2002 Accord Coupe, LX, V6, Satin Silver over Charcoal (81K miles)
VIN: 1HGCG224X2A011655

If you're going to include inflation in determining the 10-yr cost of buying aftermarket paper filters, then you should also include the amount of money you'll spend on recharging kits during that same time span.

Plus, if you want to take it to a whole new level, what about the opportunity cost by spending $46 now versus spending $10 every two years and investing the balance of the total and earning interest?

It's late, so I hope I'm making sense.

Reciprocally, I must disagree with your (somewhat) flawed cost analysis. We need to look at everything in terms of "constant dollars," over time. Based upon historical data, we must (reasonably) assume an annual inflation rate.

I wouldn't call my cost analysis "flawed" b/c I didn't provide a "cost analysis." Instead I provided a simplified example in an attempt to prove my point - for your 10yr/100K car example the cost diff b/w a K&N and 4-5 aftermarket air filters is trivial. I took Engineering Economics 101 as well, so here are a few other ways to think about it:

1) I only actually need to buy 4 aftermarket filters over 10 years b/c the OEM one in the car covers the first two years. I wait for a sale at one of the chains, buy 4 for <$40 and put them on a shelf. On the same day you buy your $46 K&N + kit. If you really want to make this complex you should add your labor cost to clean your filter several times. I only need to pull a clean filter off my shelf every two years.

2) Like sjlee said...If I instead spread my purchase of the 4 filters over the 10 year life I can invest the money up front and draw it down as needed. Your $46 is sunk up front. Even with an ultra conservative bond or TIPS fund I can assume I'll beat or at least match inflation, which puts me well under your $46 K&N.

I bought my K&N cone filter on ebay for $22 shipped. :nuts:

To All:

Fair enough, Gentlemen. As Cajun points out, my $46 is an "up-front, sunk cost." And I have no REAL idea of how many uses I can get out of this K&N "cleaner/recharger" kit.

But for NOW, let's skip the money. My motives for a K&N conversion were NOT solely based upon "Economics."

I am NOT so much interested in any "performance" gain as I am in maximizing engine PROTECTION. THAT was my principal motive in purchasing a K&N air filter element!

Robert Warden
BSME (retired)

**********************************
1986 Accord Hatchback, LX-i, 5-speed, Misty Beige Metallic over Silky Red (216K miles)
VIN: 1HGBA5348GA167648
2002 Accord Coupe, LX, V6, Satin Silver over Charcoal (81K miles)
VIN: 1HGCG224X2A011655

A very interesting discussion. But I don't think it makes that much difference. I had the dealer change my air filter at 93,000 miles, while he replaced my timing belt. My gas milage has remained the same, and the engine is going strong at 110,000 miles. I don't live in a very dusty environment. I have never changed air filters on any Honda I have owned until they need a timing belt change. I have owned four plus a 97 Fit. They have all gone over 100,000 miles, except the Fit, without any major engine problems.

A very interesting discussion. But I don't think it makes that much difference. I had the dealer change my air filter at 93,000 miles, while he replaced my timing belt. My gas milage has remained the same, and the engine is going strong at 110,000 miles. I don't live in a very dusty environment. I have never changed air filters on any Honda I have owned until they need a timing belt change. I have owned four plus a 97 Fit. They have all gone over 100,000 miles, except the Fit, without any major engine problems.

Woah! You must live with some CLEAN air! My air filter is WAY overdue if I wait until 30K, I don't think the engine would run properly if I waited that long.

To All:

Fair enough, Gentlemen. As Cajun points out, my $46 is an "up-front, sunk cost." And I have no REAL idea of how many uses I can get out of this K&N "cleaner/recharger" kit.

But for NOW, let's skip the money. My motives for a K&N conversion were NOT solely based upon "Economics."

I am NOT so much interested in any "performance" gain as I am in maximizing engine PROTECTION. THAT was my principal motive in purchasing a K&N air filter element!

Robert Warden
BSME (retired)

**********************************
1986 Accord Hatchback, LX-i, 5-speed, Misty Beige Metallic over Silky Red (216K miles)
VIN: 1HGBA5348GA167648
2002 Accord Coupe, LX, V6, Satin Silver over Charcoal (81K miles)
VIN: 1HGCG224X2A011655

If your main goal is to maximize your engine protection, then the K&N is NOT the way to go. Paper filters do a better job of filtering than reusable filters.

http://www.duramax-diesel.com/spicer/index.htm
http://www.bobistheoilguy.com/airfilter/airtest3.htm

Sjlee:

Thank You for the links. What I see are some pretty discouraging empirical data in the test results, respective to using a K&N air filter. The paper filters apparently do a much better job.

Therefore, it seems like I've wasted a bit of money (about $65 for two filters, plus $10 for a "cleaner/charger" kit). But at least my (ostensible) mistake hasn't produced a catastrophic loss.

I am now inclined to revert to an OEM paper-element air filter. As I recall, Honda uses Filtech, Inc. as the vendor on my '02 V6...and likely also for my '86 I-Four.

I THINK perhaps I should stop trying to "re-engineer" things and stick purely with Honda OEM. But at times, my being fallible, I am also subject to being taken in by clever, marketing hyperbole. Ah yes...live and LEARN!

Anybody wanna buy a couple of K&N air filters, on the cheap? I'll throw in the "cleaner/charger" kit for free.

Robert Warden
BSME (retired)

**********************************
1986 Accord Hatchback, LX-i, 5-speed, Misty Beige Metallic over Silky Red (216K miles)
VIN: 1HGBA5348GA167648
2002 Accord Coupe, LX, V6, Satin Silver over Charcoal (81K miles)
VIN: 1HGCG224X2A011655

I stick with Honda OEM for some stuff (trans fluid, coolant, PS fluid, etc.), but not air filters. Cut your K&N losses by going with a Purolator air filter (vs. OEM).

Sjlee:

Thank You for the links. What I see are some pretty discouraging empirical data in the test results, respective to using a K&N air filter. The paper filters apparently do a much better job.

Therefore, it seems like I've wasted a bit of money (about $65 for two filters, plus $10 for a "cleaner/charger" kit). But at least my (ostensible) mistake hasn't produced a catastrophic loss.

I am now inclined to revert to an OEM paper-element air filter. As I recall, Honda uses Filtech, Inc. as the vendor on my '02 V6...and likely also for my '86 I-Four.

I THINK perhaps I should stop trying to "re-engineer" things and stick purely with Honda OEM. But at times, my being fallible, I am also subject to being taken in by clever, marketing hyperbole. Ah yes...live and LEARN!

Anybody wanna buy a couple of K&N air filters, on the cheap? I'll throw in the "cleaner/charger" kit for free.

Robert Warden
BSME (retired)

**********************************
1986 Accord Hatchback, LX-i, 5-speed, Misty Beige Metallic over Silky Red (216K miles)
VIN: 1HGBA5348GA167648
2002 Accord Coupe, LX, V6, Satin Silver over Charcoal (81K miles)
VIN: 1HGCG224X2A011655

Just to be clear, I am not saying that K&N air filters are not useful... it really depends on what your goal is. They do allow better airflow, so if you have mods that'll take advantage of this, you'll get increased engine performance. Other than that, I think it's debatable if there is much (if any) financial gain by using one. In addition, some argue about the environmental benefits (less air filters going into landfills), but I'd argue that the chemicals used to maintain the filters are as bad (or worse) for the environment.

As far as paper air filters, I've found that some aftermarket brands work just as well as OEM, but are much less expensive. I just purchased a Microgard (made by Purolator) one for our Pilot, and it looked comparable to OEM. In addition, despite what you may think about Fram oil filters, their air filters are good.