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