High Flow Washable Air Filter Brands?
 

On my wife's 2008 Altima I'm trying to find a better flowing air filter that drops in place of the original. My preference would be to use the AFE Pro Dry S, wich is synthetic, dry (not oiled), and washes with soap and water. It's high flowing, and filters over 99% which is much better than standard cotton gauze cleanables like K&N (95%).

Well AFE doesn't make a filter for the 4 cylinder Altima 2008 model. So besides K&N, what are my options? I've searched for hours and can't seem to find anything. My only option seems to be installing a universal cone filter but my wife won't like that because it's noisy. It's her car and she'll ***** about the noise.

I installed the K&N on my 350Z and noticed a mileage increase of maybe 1-2 mpg on average. The downside is the oil is horribly dirty now. Proof of the poor filtering of K&N can be found by looking at the thousands of oil analysis posts people are sharing on bobistheoilguy.com forum. They are anal about making one change and then doing an oil sample analysis at the next oil change. They all have solid proof that installing a K&N filter causes a huge amount of silicone to show up in the oil. I'm also proof. My oil has always been clean, I let the car warm up before hard accelerations and do on time changes. However after installing the K&N my oil turned dark brown within months. That dirt is entering the engine through the cylinders and scraping past the rings...... bad news.

Does anyone know of a brand that makes high flow filters for a 2008 Altima 2.5S model?

I had a K&N filter on my Ranger. It was a toxic nightmare to clean (washing out all that old oil), and I believe that the oil gunked up my MAF sensor. I now just run disposables.

I like the high flow filters simply because there's a lower differential pressure across the inlet and outlet side of the filter. This means you don't step as far down on the accelerator to get the same rpm when the vehicle is under load in gear. Over the life of that filter I could save a hundred gallons (maybe??). The other + side is that I don't ever have to buy a filter again, just clean and reuse, which promotes more frequent filter cleaning because it's FREE. By cleaning more often I've gone full circle by having a full time clean filter that also flows better, and never have to spend money buying new filters...

But with K&N that's all out the window. I'd have to buy their oil kit. Then if I over oil it I get a dirty MAF, which will destroy mpg- or possibly just shut the engine down.

I am strongly STRONGLY against this type of filter. The job of a filter is first, and foremost, to filter. Run through bobistheoilguy.com and see all of the crap that gets by the filter (and shows up in oil analysis).

My opinion was recently validated by a professor of mine (now former professor) who calls them garbage... His credentials are many of years as an F1 engineer/machinist/crewman. I'm going to miss that class and his awesome stories :p

Besides, autospeed did a write up on pressure differential across the filter element... The dirtiest filter really showed no signs of pressure drop.


I inspect my filter - and replace when the rubber seal falls apart such that it won't seal. Oil analysis shows nominal silica - that's good enough for me :)

I'm not out to debate whether using this filter is better or worse, I've been reading all the oil sample analysis results on BITOG for a year now. I'm trying to find a list of companies besides K&N who make them for my application. I hate the K&N, even though installing it increased my miles per gallon on my 350Z by 1-2 mpg overall.

The rubber seals are pretty important too, I had a small piece of TREE BARK that got past the rubber seal on the K&N filter on my 350Z. It wedged itself onto the MAF and stalled the car while I was accelerating onto the turnpike. Even though the car was plastered with tree bark so badly that the lugnut holes on the wheels were packed solid, it's still no excuse to get past that rubber seal. We had a tornado that ripped the hangar doors off our building, and totalled 16 airplanes on the airport, and moved my car halfway into the next parking space- then when I drove home the car dies and I find tree bark stuck in the MAF...... I reallly really hate the K&N now.

High flow air filters do not improve fuel economy. They may give you a tiny bit more horsepower, but its been tested here and they don't improve fuel economy. As Treb said, the effects of even a dirty filter are next to no pressure drop across the filter. Go with an oem or quality oem replacement.

...and ONLY at WOT, I'd wager. How much of the time does your wife drive at WOT?

As for your "1-2 mpg increase", I'd say that's the placebo effect, measurement error, or both.

metrompg did a full test of pods, paper element and no filter setups with almost no difference in FE, only to find that standard filter is probably best as it maintains low torque which is what slow drivers want

I'm pretty sure he is looking for a performance filter because they are reuseable. they instructions for those kits(if read carefully) typically tell you to clean them frequently. By frequently I took that to mean about every 1,000 miles.

There are a couple brands out there that use a powder coating instead of the oil. There are also a few that have no coating whatsoever and just use more restrictive filters per square inch but have much more square footage. I tried to do a little research for you but most of the sites did not specify if they were oil, if they were powder(or how to obtain later after several washes) and things of that nature. Phone calls would be in order for that. I'm not quite altruistic so I stopped short of making those lol ^_^.

Airaid had a few models that looked promising(were very large).

amsoil filter

The aforementioned autospeed article

Don't Bother Changing the Factory Filter


:thumbup:

Which is why I don't bother changing my old air filter.... It's flowing fine and lab testing shows its filtering :thumbup:

Oh, I had actually never thought of just replacing the filter.

If you were looking to add HP it defeats the purpose of Cold air intake anyway. The point of CAI is to get the filter as far from the engine as possible. The filter can work as a heat exchanger rather effectively. So moving the filter away from the engine(towards an air port on your car(AWAY FROM WATER)) means the filter will only get as warm as the air temperature and therefore not pre-heat the air leading to less available HP. It's the same reason tunres avoid TMIC(Top-Mounted Inter-Coolers(which ought to be Pre-Cooler)) because it "soaks" in the heat emitted from the engine and defeats some of the effectiveness of the intercooler.

What the above website did suggest is the airbox itself is likely the problem.

I can agree there. The stock piping for my Del Sol was much narrower than the carbon fiber tube that leads directly to a decent gap in the engine bay that is protected from water by the front bumper, hood, and the plastic in the wheel well(that keeps mud from being thrown all over the inside of your bumper). The new filter has a much larger surface than the old box, much finer thread count(pumped water across both for testing), and much less restrictive piping.

Changing just the air filter is not worth it, that seems somewhat apparent(it can't possibly be much bigger if it goes in the same box and its still going to heat soak)

So yeah I would look for a full CAI drop in, although I am not in any way sure of how this will influece your MPG. More air might boost, but the air is not going to recieve any pre-heating.

I thought that's what the OP was talking about - he never mentioned anything about cold air :thumbup:

I'm curious, however, of what the temperature rise is through a stock heat soaked intake system.... Most parts nowadays are plastic - so there's low heat transfer coefficients and thermal mass... Except for the manifold and TB - where airflow is really fast offering little time for heat up. I guess I'll add that to the list of experiments (maybe a good reason to upgrade multimeters to one that can accept a thermocouple :D)

[QUOTE=trebuchet03;76999]I thought that's what the OP was talking about - he never mentioned anything about cold air :thumbup:

QUOTE]
Oh no, looking at it now thats what he meant I think. I just had never considered it because the very first time I saw anyone do it it was CAI. That person then proceeded to do CCAI(Complete Cold Air Intake) using exhaust heat to run a small compressor alongside his supercharger. He used the turbine fins to power the compressor and supercharged off the block.

It was a 42. . .428 Cobra engine in a Ford Torino. It might have been a 427. . . he has two and both motors. Thats kind of outside the realm of normal though because he had everything built custom to be able to take the chilled air and increased compression. I will say the car can pin you to your seat if you give the compressor a minute or so to start cooling. Can't run it for more than a few minutes full out otherwise the oil doesn't drip down fast enough to get back in the engine ^_^(with an expanded oil pan).

It's not FE. I'm not even going to pretend it is lol

I can't tell you exact temperatures, but a few years back I did some testing with phenolic insulators to block heat from the head getting into the manifold. It was a performance modification and a successful one. But, the testing showed some very interesting info. You can see it here:

Intake Manifold Insulators

Wow that is interesting Daox!

Just by switching out for insulation that thin made a rather drastic difference.

I assumed using carbon fiber over anything else would provide an advantage since you can feel the heat soak through the hood. . . Obviously for performance sake it would be wise to extend the small heat shield engine-side of my air intake all the way to the manifold

Ok so to better understand what I'm looking for, I'll explain my original post a little differently. First and foremost I want a reusable, washable air filter. Various reasons include: 1) not ever having to buy another filter unless it's physically damaged, 2) I can clean the filter at every oil change or even more frequently if I choose to, 3) I won't be throwing away air filters into the public landfills every 10,000 miles, 4) Manufacturers won't waste tons of energy making these filters because I won't be replacing them, 5) in my area there is a lot of road construction which causes my filter to get dirty very often.

Now again, without DEBATING whether you would like to install a washable air filter on YOUR vehicle, does anyone know who makes them besides K&N, AFE, AEM, and Green Filter? Because I'd like to install one on my vehicle. My vehicle is kind of new and hard to find parts like this for right now.

THEUNCHOSEN brought up a great point that I had never heard of, which is that some filters use a powder instead of oil. That's really interesting, I've never heard of this. Do you know what brands? I'm thinking the powder plugs all the larger holes first and probably makes the filter a little easier to clean since the dirt rests on top of the powder.

I absolutely do NOT want anything to do with a "cold air intake" period. That will instantly lower the gas mileage not only in theory by needing more fuel to meet the more dense air charge, but also by seeing it first hand on several vehicles of my own. Cold air is more dense period. On my explorer I modified the stock airbox and put the factory inlet tube on the hot engine side and blocked the cold air side. The IAT sensor is showing about a 30 degree higher temp on average but gets even higher at low speeds. As a result the truck uses less fuel, and has a lower fuel flow to match the less dense air. I'm designing an on-demand blend valve that switches from hot to cold intake for when I'm towing and pulling onto the interstate.

:thumbup:

Not to diverge too far off topic... But how did you test HP? Awesome documentation though :thumbup::thumbup:

well I found this company

ITG Air Filters US Distributor - Profilters, Maxogen and Megaflow Air Filters : ITG Profilters

No oil needed for the profilter version. No user experience and not sure what car model we are talking about so I can't tell you if they have your car.

Oh, sorry I was not suggesting installing a cold air intake. It brought to mind maybe using wide diameter steel tubing leading to your air box so the engine doesn't have to fight to pull the air. That said I don't know what your current piping looks like so it might not matter.