It's about time to replace my air filter and was wondering if I should replace it with a K&N air filter. So far, I have heard only good things about K&N filters, but any input is welcome. Are they any good? Are they worth the price (its about 4-5 times more expensive than the cheapest filter I can find)? If you have any experiences with K&N filter, feel free to sound off here.

I've heard they do add a little horsepower.

I have one on my 91'Caprice Classic, I use to get around 300 miles on a full tank(305c.i.)on now I get around 360 on a full tank!! -Hell gas prices these days,It payed for itself on the 3rd time I filled it up!!-K&N,a bit more horsepower,and fuel saver!!

I'd say go for it, Ive used them and never had a problem

just oil it reguraly and your good to go. If you have some extra dough, buy the new X-stream stop to go with your filter, itll take place of your ugly top bell, and help a bit more with effinecy.

Here is a link to an article that I found very interesting. http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm They tested K&N filters against other aftermarket and OEM filters and came up with some interesting results in which filters capture and hold dirt,how much dirt actually got through, flow restriction, and dust loading. The last 4 paragraphs and the charts say a lot about the claims of filter manufacturers. I thought it was a very informative article and helped me to know i have been using the right filter in my vehicles all these years.

umm... so which is the best...

im guessing that the AC Delco was the winner, but there needed to be an overview, where everything was laid out visually, like the graphs.

umm... so which is the best...

im guessing that the AC Delco was the winner, but there needed to be an overview, where everything was laid out visually, like the graphs.
Yes, the AC Delcos were the winners as pointed out by the graphs. The last 4 paragraphs of the report act as a summary/overview,( that's why I said in my post above to check out these last 4 paragraphs.) This quote from the report says a lot,"Now I am not saying that ALL aftermarket filters are useless. However, if a filter is using "better airflow" as their marketing tool, remember this....Does it flow better? At very high airflow volumes, probably. The stock filter will flow MORE THAN ENOUGH AIR to give you ALL THE HORSEPOWER the engine has to give. And this remains true until the filter is dirty enough to trip the air filter life indicator. At that point performance will decline somewhat. Replace the filter and get on with it."

I changed over to a K&N because I was looking for the long-term savings over disposable filters. Along with a performance exhaust it is totally worth it and I would do it again, however, I had serious problems with the filter gunking up my MAF right out of the box. Luckily a couple of treatments of brake cleaner took care of it, but in theory it could destroy the sensor. My engine has also reached the point where I don't believe the excess dirt a K&N will let through will cause negative results before its natural death.

If those tests are to be believed, then it would indicated, to me at least, that the AC Delco filter was the best and that K&N actually had one of the worst filters. The only thing I don't like about that test is that it looked like it only test one filter application by each manufacturer. Performance for one application might indicate overall the effectiveness of the whole brand. The reason I see this as an issue is that different designs will flow differently and different amounts. For example, I'm sure the round design of the boxy Caprice air filter flows a different amount than the filters used by the '91-93 Caprice and I'm sure those flow a different than the '94-96 filters (since each design is different).

That and they were used on diesel trucks.

I dont doubt the more dirt thing through a K&n cause it less restrective.

Ehh, little dirt never hurt no one, Go for a K&N I've never heard, or seen a engine be destroyed cause a K&n was used

seems like a huge waste of time (the test i mean)
the differences between the filters LOOKED big on the graphs, but it was only 2-3 percent in some cases

seems like a huge waste of time (the test i mean)
the differences between the filters LOOKED big on the graphs, but it was only 2-3 percent in some cases

that is true, cause none of the graphs start at Zero.

I can believe and not believe these tests.

Like I said before, ive never seen, or heard of K&N filters hurting a engine, just over oiling can cause problems, but you have to be a idiot to do that.

This same discussion came up at work on one of the electronic boards. Normal air filters have always been fine for me. But here is the post, so take from it what you will, for I thought that this guy made some good points and was informative.

>>>>>>>>>>>>>>>>>>>>>>
Ok. I know this will stir things up and there will be folks that won't
believe me and argue this point, but this is the undisputed truth from a
technical engineering perspective.

Free flowing air filters will NOT improve fuel economy PROVIDED that you are
not at WOT (Wide Open Throttle) or near WOT all the time. That is, for
normal driving (partially open throttle), free flowing air filters will NOT
improve fuel economy. All advertising claiming better fuel economy is
marketing, but technically, it's not false advertising because you could
improve fuel economy if the engine is operated at or near WOT. Going one
step further, a dirty air filter will NOT decrease fuel economy provided
you're operating at part throttle conditions.
Now - this statement is for gas engines. Diesels, which have no throttle
and operate at WOT all the time, will show improved fuel economy with a free
flowing (or clean) air filter.
This is why: The air filter (besides filtering the air) affects the
efficiency of an engine (i.e. the fuel economy) in one manner only - it acts
as a restriction to the intake side (induction) and increases the pumping
losses. Pumping losses is a term automotive engineers use to describe the
loss in efficiency due to a partially closed throttle. Google this term if
you're not familar with it. I'll copy an excerpt from a BMW valvetronic web
site here:

"At light throttle, the throttle butterfly partially or even nearly closes.
The pistons are still running, taking air from the partially closed intake
manifold. The intake manifold between the throttle and the combustion
chamber has a partial vacuum, resisting the sucking and pumping action of
the pistons, wasting energy. Automotive engineers refer to this phenomenon
as "pumping loss". The slower the engine runs, the more the throttle
butterfly closes, and the more energy is lost. "

Here's the deal - at part throttle, you have pumping losses. Assume you
normally cruise at 10% open throttle to maintain 40mph on a certain road.
Now, assume I put duct tape over your throttle and close 50% of it off (i.e.
simulating a really clogged air filter - big restriction), now you'll need to open your throttle 60% to maintain that 10% opening and to maintain your
speed. (I realize it's not quite linear like that, but these numbers are
close enough to get the point across). Do you lose fuel economy with this
duct tape on? No - not at this operating point. The point is, the engine
is experiencing the same pumping loss at this operating point regardless of
whether the throttle is closed by the throttle blade, a clogged air filter,
or duct tape.
The only thing a dirty air filter does is cause you to open your throttle
more to compensate for the decreased air flow as indicated in our example
above. The pumping losses are the same regardless of whether your throttle
is open 10% (let's say with no air filter), 15% (with a free flowing or
clean filter) or 60% (with the duct tape), so your efficiency and thus fuel
economy are the same.

Now, this is for partially open throttles only, here the AF (air fuel) ratio
is maintained at 14.7:1. At or near WOT, in calibration we go into PE
(power enrichment) or COT (converter overtemp protection) where the AF ratio is skewed richer for more power or overtemp protection. As long as the
intake restriction isn't so severe that you must open the throttle enough to
enter these modes, you won't experience any fuel economy loss.
I know people will have personal experience to the contrary, but they're
probably because a tune-up was done at the same time the filter was changed, or something else was done, driving habits changed, etc.

This "dirty air filter decreasing fuel economy myth" was a topic of
discussion on a recent drive trip I had with GM powertrain engineers - we
were discussing pumping losses and DOD (Displacement on Demand - V8s running in 4 cylinder mode), which by the way, get their fuel economy gains purely by the decrease in pumping losses when in 4 cyl mode. We were also
discussing the old misconception that a V8 could get better fuel economy
than a 4 cyl on a light highway cruise because you're barely into the
throttle, whereas in the 4 cyl, you may have the throttle 50% open to
maintain the same speed. The 4 cyl will get better fuel economy with the
50% open throttle by the way due to the decrease in pumping losses, contrary to what many hot rodders believe.

I haven't really thought the cold air induction kit issue through. Will
getting colder, denser air improve fuel economy? You get more power (more
efficiency) with less volume of air because it's denser, hence you don't
need as much air volume, so your throttle blade won't need to be open as
much, hence more pumping losses. So I'm not sure if a cold air induction
system will increase fuel economy either. You do get more power at WOT with colder denser air and less intake restriction though, that's not being
disputed.
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

wow, very interesting about the cold air intake.
as for the duct tape idea, this couldnt work on a carb. the AF ratio is dependant on a free flow of air into the carb.

padgettra's post above says some of the things I meant to say when I posted the link about the air filter test. It was for information purposes only to help consumers realize that some of the advertising they see about products isn't always the full truth. I worked in auto parts stores many years ago and came across many products that made claims to "improve" vehicle performance, etc. A lot of these products are no longer around and one should thoroughly look into a product's claim(s) before spending a lot of money into something that may not work as advertised. Companies can make all sorts of claims and have all sorts of "research" and facts to back it up. As an example, Company X claims their product can improve gas mileage. What they don't tell you is that when they ran tests with their product it only improved mileage by 1/10 of 1 %. It still is an improvement, albeit a minute one,but the company can make the claim that it is a better product. The FTC is a government agency charged with keeping an eye on companies, to make sure that they don't have false and deceptive advertising. Sometimes, these ads and claims slip through the cracks for one reason or another. I'm not saying K&N ads are false. As reported above, they may not be the best choice for ALL vehicles, depending upon each vehicle's needs,operating conditions, and other factors. So K&N or some other "high performance" filter may end up being an unneccessary cost where an OEM filter may be a better choice.
BTW- The original post that mentioned this survey can be found here:http://www.automotiveforums.com/vbulletin/showthread.php?t=579458

Those are some good points about the air supply/demand, but as long as a reusable air filter doesn't cause damage to the engine I still say go for it. A K&N on sale is five times the price of a stock air filter, so after 50,000km mine has paid for itself, and the cost of a recharge kit evry 50,000 is much less than 5 air filters. Or to look at it another way that's 2.5 air filters I can keep out of a landfill each year...

This same discussion came up at work on one of the electronic boards. Normal air filters have always been fine for me. But here is the post, so take from it what you will, for I thought that this guy made some good points and was informative.

>>>>>>>>>>>>>>>>>>>>>>
Ok. I know this will stir things up and there will be folks that won't
believe me and argue this point, but this is the undisputed truth from a
technical engineering perspective.

Free flowing air filters will NOT improve fuel economy PROVIDED that you are
not at WOT (Wide Open Throttle) or near WOT all the time. That is, for
normal driving (partially open throttle), free flowing air filters will NOT
improve fuel economy. All advertising claiming better fuel economy is
marketing, but technically, it's not false advertising because you could
improve fuel economy if the engine is operated at or near WOT. Going one
step further, a dirty air filter will NOT decrease fuel economy provided
you're operating at part throttle conditions.
Now - this statement is for gas engines. Diesels, which have no throttle
and operate at WOT all the time, will show improved fuel economy with a free
flowing (or clean) air filter.
This is why: The air filter (besides filtering the air) affects the
efficiency of an engine (i.e. the fuel economy) in one manner only - it acts
as a restriction to the intake side (induction) and increases the pumping
losses. Pumping losses is a term automotive engineers use to describe the
loss in efficiency due to a partially closed throttle. Google this term if
you're not familar with it. I'll copy an excerpt from a BMW valvetronic web
site here:

"At light throttle, the throttle butterfly partially or even nearly closes.
The pistons are still running, taking air from the partially closed intake
manifold. The intake manifold between the throttle and the combustion
chamber has a partial vacuum, resisting the sucking and pumping action of
the pistons, wasting energy. Automotive engineers refer to this phenomenon
as "pumping loss". The slower the engine runs, the more the throttle
butterfly closes, and the more energy is lost. "

Here's the deal - at part throttle, you have pumping losses. Assume you
normally cruise at 10% open throttle to maintain 40mph on a certain road.
Now, assume I put duct tape over your throttle and close 50% of it off (i.e.
simulating a really clogged air filter - big restriction), now you'll need to open your throttle 60% to maintain that 10% opening and to maintain your
speed. (I realize it's not quite linear like that, but these numbers are
close enough to get the point across). Do you lose fuel economy with this
duct tape on? No - not at this operating point. The point is, the engine
is experiencing the same pumping loss at this operating point regardless of
whether the throttle is closed by the throttle blade, a clogged air filter,
or duct tape.
The only thing a dirty air filter does is cause you to open your throttle
more to compensate for the decreased air flow as indicated in our example
above. The pumping losses are the same regardless of whether your throttle
is open 10% (let's say with no air filter), 15% (with a free flowing or
clean filter) or 60% (with the duct tape), so your efficiency and thus fuel
economy are the same.

Now, this is for partially open throttles only, here the AF (air fuel) ratio
is maintained at 14.7:1. At or near WOT, in calibration we go into PE
(power enrichment) or COT (converter overtemp protection) where the AF ratio is skewed richer for more power or overtemp protection. As long as the
intake restriction isn't so severe that you must open the throttle enough to
enter these modes, you won't experience any fuel economy loss.
I know people will have personal experience to the contrary, but they're
probably because a tune-up was done at the same time the filter was changed, or something else was done, driving habits changed, etc.

This "dirty air filter decreasing fuel economy myth" was a topic of
discussion on a recent drive trip I had with GM powertrain engineers - we
were discussing pumping losses and DOD (Displacement on Demand - V8s running in 4 cylinder mode), which by the way, get their fuel economy gains purely by the decrease in pumping losses when in 4 cyl mode. We were also
discussing the old misconception that a V8 could get better fuel economy
than a 4 cyl on a light highway cruise because you're barely into the
throttle, whereas in the 4 cyl, you may have the throttle 50% open to
maintain the same speed. The 4 cyl will get better fuel economy with the
50% open throttle by the way due to the decrease in pumping losses, contrary to what many hot rodders believe.

I haven't really thought the cold air induction kit issue through. Will
getting colder, denser air improve fuel economy? You get more power (more
efficiency) with less volume of air because it's denser, hence you don't
need as much air volume, so your throttle blade won't need to be open as
much, hence more pumping losses. So I'm not sure if a cold air induction
system will increase fuel economy either. You do get more power at WOT with colder denser air and less intake restriction though, that's not being
disputed.
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

Good info there Padgettra

About the cold air air intake thing.
Yes cooler outside air helps.
Most Oem filter setups already have a true forced cold air intake.
True forced Cold air intake is outside cold air that is forced in threw the grille or fender area when you are driving down the road.
Some air intake kits are not even true outside air intake setups.
A few I have saw even pulled hot air from under the hood threw a hot crome pipe and had a resister wired into the intake air tempture sensor to fool the PCM into thinking it was getting cold air.
MT

This same discussion came up at work on one of the electronic boards. Normal air filters have always been fine for me. But here is the post, so take from it what you will, for I thought that this guy made some good points and was informative.

>>>>>>>>>>>>>>>>>>>>>>
Ok. I know this will stir things up and there will be folks that won't
believe me and argue this point, but this is the undisputed truth from a
technical engineering perspective.

Free flowing air filters will NOT improve fuel economy PROVIDED that you are
not at WOT (Wide Open Throttle) or near WOT all the time. That is, for
normal driving (partially open throttle), free flowing air filters will NOT
improve fuel economy. All advertising claiming better fuel economy is
marketing, but technically, it's not false advertising because you could
improve fuel economy if the engine is operated at or near WOT. Going one
step further, a dirty air filter will NOT decrease fuel economy provided
you're operating at part throttle conditions.
Now - this statement is for gas engines. Diesels, which have no throttle
and operate at WOT all the time, will show improved fuel economy with a free
flowing (or clean) air filter.
This is why: The air filter (besides filtering the air) affects the
efficiency of an engine (i.e. the fuel economy) in one manner only - it acts
as a restriction to the intake side (induction) and increases the pumping
losses. Pumping losses is a term automotive engineers use to describe the
loss in efficiency due to a partially closed throttle. Google this term if
you're not familar with it. I'll copy an excerpt from a BMW valvetronic web
site here:

"At light throttle, the throttle butterfly partially or even nearly closes.
The pistons are still running, taking air from the partially closed intake
manifold. The intake manifold between the throttle and the combustion
chamber has a partial vacuum, resisting the sucking and pumping action of
the pistons, wasting energy. Automotive engineers refer to this phenomenon
as "pumping loss". The slower the engine runs, the more the throttle
butterfly closes, and the more energy is lost. "

Here's the deal - at part throttle, you have pumping losses. Assume you
normally cruise at 10% open throttle to maintain 40mph on a certain road.
Now, assume I put duct tape over your throttle and close 50% of it off (i.e.
simulating a really clogged air filter - big restriction), now you'll need to open your throttle 60% to maintain that 10% opening and to maintain your
speed. (I realize it's not quite linear like that, but these numbers are
close enough to get the point across). Do you lose fuel economy with this
duct tape on? No - not at this operating point. The point is, the engine
is experiencing the same pumping loss at this operating point regardless of
whether the throttle is closed by the throttle blade, a clogged air filter,
or duct tape.
The only thing a dirty air filter does is cause you to open your throttle
more to compensate for the decreased air flow as indicated in our example
above. The pumping losses are the same regardless of whether your throttle
is open 10% (let's say with no air filter), 15% (with a free flowing or
clean filter) or 60% (with the duct tape), so your efficiency and thus fuel
economy are the same.

Now, this is for partially open throttles only, here the AF (air fuel) ratio
is maintained at 14.7:1. At or near WOT, in calibration we go into PE
(power enrichment) or COT (converter overtemp protection) where the AF ratio is skewed richer for more power or overtemp protection. As long as the
intake restriction isn't so severe that you must open the throttle enough to
enter these modes, you won't experience any fuel economy loss.
I know people will have personal experience to the contrary, but they're
probably because a tune-up was done at the same time the filter was changed, or something else was done, driving habits changed, etc.

This "dirty air filter decreasing fuel economy myth" was a topic of
discussion on a recent drive trip I had with GM powertrain engineers - we
were discussing pumping losses and DOD (Displacement on Demand - V8s running in 4 cylinder mode), which by the way, get their fuel economy gains purely by the decrease in pumping losses when in 4 cyl mode. We were also
discussing the old misconception that a V8 could get better fuel economy
than a 4 cyl on a light highway cruise because you're barely into the
throttle, whereas in the 4 cyl, you may have the throttle 50% open to
maintain the same speed. The 4 cyl will get better fuel economy with the
50% open throttle by the way due to the decrease in pumping losses, contrary to what many hot rodders believe.

I haven't really thought the cold air induction kit issue through. Will
getting colder, denser air improve fuel economy? You get more power (more
efficiency) with less volume of air because it's denser, hence you don't
need as much air volume, so your throttle blade won't need to be open as
much, hence more pumping losses. So I'm not sure if a cold air induction
system will increase fuel economy either. You do get more power at WOT with colder denser air and less intake restriction though, that's not being
disputed.
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

Good info there Padgettra

About the cold air air intake thing.
Yes cooler outside air helps.
Most Oem filter setups already have a true forced cold air intake.
True forced Cold air intake is outside cold air that is forced in threw the grille or fender area when you are driving down the road.
Some air intake kits are not even true outside air intake setups.
A few I have saw even pulled hot air from under the hood threw a hot crome pipe and had a resister wired into the intake air tempture sensor to fool the PCM into thinking it was getting cold air.
MT

Has anyone tried something like this? It looks great, in terms of a cold air intake. Ebay Cold Air Intake (http://cgi.ebay.com/ebaymotors/94-96-Impala-SS-Caprice-LT1-Ram-Air-intake-system_W0QQcmdZViewItemQQcategoryZ38634QQihZ004QQi temZ140030154686QQrdZ1)

Has anyone tried something like this? It looks great, in terms of a cold air intake. Ebay Cold Air Intake (http://cgi.ebay.com/ebaymotors/94-96-Impala-SS-Caprice-LT1-Ram-Air-intake-system_W0QQcmdZViewItemQQcategoryZ38634QQihZ004QQi temZ140030154686QQrdZ1)

The good part it looks like a true cold air intake.
The air filter I am not sure what type or brand.
But there may be one problem.
The intake looks like it is mounted below the bumper.
It would scoop up water if your run threw any deep water you would hydro lock the engine real fast.
I have replace a few engines that had the intake mounted right over the bumper.
Older Ford rangers had the air intake right over the bumper on OEM air intake setup.
Right over or under the bumper mounting on intak you want to stay away from water with them.
MT

Yeah that intake is for sunny weather only.

RAI is a better alternative if you live in a wet area.

Ok, what is RAI? Ram Air Intake I assume? How do you put that on a vehicle like this?

I know there are some made for the TBI that was used.

Theres a impala forum or something arund here with a DIY RAI intake.

its like a round dish over the TBI unit, onto a tube to one of the sides for about a foot or two then some round filter on the end. usually K&N

take your pic http://search.ebay.com/search/search.dll?sofocus=bs&sbrftog=1&from=R10&catref=C6&satitle=chevy+ram+air+intake&sacat=-1%26catref%3DC6&sargn=-1%26saslc%3D2&sadis=200&fpos=ZIP%2FPostal&ftrt=1&ftrv=1&saprclo=&saprchi=&fsop=1%26fsoo%3D1&fgtp=

I was thinking the one I posted would be superior because it would actually draw cold air instead of engine air. Yet, it would be bad for a wet climate.

I was thinking the one I posted would be superior because it would actually draw cold air instead of engine air. Yet, it would be bad for a wet climate.

its bad in all areas, Puddles, dirt, sand. What ever is on the road will probably make its way in there. Just water is the worst cause of hydrolocking.

its bad in all areas, Puddles, dirt, sand. What ever is on the road will probably make its way in there. Just water is the worst cause of hydrolocking.
Ok, I'm no expert but common sense tells me something here... Duh, dirt and sand, it's an air filter. It's designed to take care of dirt and sand. Puddles, I don't think that would create enough water to be "inhaled" by the engine. It has to travel what 1 1/2'-2' vertically against gravity to make it into the engine. I don't think it would make it that far, then it would pour out the little drain hole. However, I can understand large puddles, or frequent puddles, hence the whole wet climate. Like I said though I'm no expert.

Ok, I'm no expert but common sense tells me something here... Duh, dirt and sand, it's an air filter. It's designed to take care of dirt and sand. Puddles, I don't think that would create enough water to be "inhaled" by the engine. It has to travel what 1 1/2'-2' vertically against gravity to make it into the engine. I don't think it would make it that far, then it would pour out the little drain hole. However, I can understand large puddles, or frequent puddles, hence the whole wet climate. Like I said though I'm no expert.
yeah but High flow air filters like the kind hat would would be used on the talked about intakes, do filter well, but they let a little more stuff through then paper ones. See the link on the first page about the tests

And yes water has to travel far, but you gotta remeber how many times the engine will make vaccum and the open the intake valve and all the air will move into the vaccum. it happens a fucking a lot. so getting the water to travel is very easy once its on/ in side the filter

A puddle, just one can be enough to hydro lock a engine.

common sense isnt always right.