I have a K&N air filter (stock housing) on my GS for the last 7K miles (over 2 years ago), and I live in a windy city where dust is a problem.
The main reason I bought the K&N filter was because it supposedly filters particles better than a standard OEM paper filter, and nobody dissuaded me against it.
Well, the tech editor of a motorcycle magazine said that claim wasn't true at all, stating that cottongauze filtration has been used for decades on race engines, where engines are torn apart after a few races, and maximum airflow is desired. He further said that if you want higher flow that's fine, but don't expect higher filtration claims, meaning your engine will definitely last less with one, especially on dusty places (like mine).
I just have borlas and the K&N, and definitely don't want to reduce engine life by having the K&N (I have them on all my vehicles now!!). If it filters at least the same as a stock filter, that's fine with me: it stays.

Any informed answers on this????
Thanks guys.

 

Juan, I have read many articles about the K&N filters. Some time ago I read an article from an indipendand researcher that tested a bunch of aftermarket filters. The filters he tested where the "open" kind. He tested K&N, Blitz, Apexi and 2 others.
The Blitz came out on top, followed closely by the K&N, the rest they tested where extremely low quility.
On a sidenote he said that the K&N filtered well becausse it was oiled, if you want to keep the filtration up, you have to take care of it thus oil it once every 10000 miles or so.
Be carefull to not drown the filter in oil, this is not good.
I have had experience with the open K&N filters and have had no problems with them if you take car of them.

Hope this info helps.

 

Thanks a lot for your reply Richie. I service the filters every 10K miles or every year, whichever occurs first. In addition, I always re-oil new filters, since they don't come very well coated from the factory. I re-oiled the GS at around 4K miles (after a year), because that oil evaporates with heat over time. One other funny recommendation by K&N is that the filter works "better" after it accumulates some miles after a cleaning (or when new). This is weird, to say the least.
My question is if the K&N, properly oiled of course, filters better, same, or worse than a OEM filter.

 

Don't you suppose, if the K&N were somehow better overall, at least ONE of the worldwide base of automotive manufacturers would be using them as an OEM source?

Putting a few miles on a K&N makes it work better...

Is very likely a true statement. When you clean and freshly "oil" the K&N you will most likely unintentionally "clog" some of the air passage "pores" with oil, reducing the airflow somewhat. After you drive the car for awhile and the filter has been under continuous "suction", the only oil left will be that absorbed into the filter fibers via capilary action.

Botton line for me is to stay with the factory recommended filters and change them often enough that the airflow is never overly restrictive.

 

It'll be the same or slightly better.

I think since you service the Filter regularly you have nothing to worry about.

Willard, I think the reason why manufacturers aren't using the K&N's is mostly due to cost.

 

can't buy into that...

Way too much good PR for K&N to land an automotive manufacturing account for them to hold a price line...

 

I don't think they make a bad product, why else would they give a milloin mile warranty ???

 

I'ved had a K&N filter in my Bronco for the last ten years the truck has over 200K miles and has never been opened.I will continue to use K&N on whatever I own.

Fernando.

 

I haven't said anything deterimental about the K&N air filter have I?

But on the other hand I'd be glad to sell you a non-functional and non-interferring device and give you a trillion miles warranty to boot.

I'm not saying the K&N is non-functional, just trying to make a point. Of course its functional, just as functional as the one the factory supplied, if not moreso.

 

Go to this link and see the air filter test

http://www.gtrowner.com/induction.html

 

That was the article I was talkin about!!!

 

I haven’t heard of an independent accredited lab doing air filtration tests on automotive filters and publishing the results. You can bet that Toyota/Lexus have done filtration tests. Lexus only recommends genuine filters.
The two tests I have read put K&N behind the OEM filter – they didn’t filter as well. Have also read of air flow meters going haywire after getting coated in filter oil.
The problem with the standard filter is that they clog up and have to be replaced often to maintain maximum flow. The K&N filter will last 50 000 km before having to be cleaned – they don’t clog up.
Personally I want my filter to clog up (then I know it is doing a good job of filtering)– if the K&N stays clean for so long where does all the dirt go?
The pressure drop across the standard filter is quite small - it is often the standard airbox that can be a problem.
BMC also manufacture cotton gauze type filters and advertise “as used in Formula 1” – so if that last 2 kW is extremely important and you rebuild your engine every three hours then they have the filter for you.
Reading the side of the pack that the filter comes in will give you warm fuzzy feelings – but do you think that the information is unbiased?
Do a couple of people saying their engine hasn’t blown up after using an after-market filter constitute a scientific test of filtration? Did they also drive the exact same vehicle the same distance at the same time with the only difference being a fully serviced Lexus filter?
The available evidence points to some after-market “filters” sacrificing filtration for flow.
I doubt anyone could pick the difference between a brand new Lexus filter and a K&N filter in the factory airbox. I have read two magazine dyno tests where swapping the (brand new) standard filter for a K&N filter made no difference on the dyno.
K&N cost up to four times as much as a Lexus filter.

So:
Lexus recommend only Lexus filters
Or you can spend a lot more money, let more dirt in, and hardly tell the performance gain.

What will you believe?

 

Juan - When I first got my '87 Corvette, I was looking for some cheap & quick performance upgrades so I bought a K&N filter which just dropped into the factory airbox. The G-Tech Pro didn't exist then but it's forerunner was the Vericom 2000 & it worked on the same principle. Anyway, I went to my "backroad dragstrip/testing facility" & made 3 runs ( 0-60 ) with the stock paper filter & then 3 with the K&N. Each run with the K&N was a full tenth quicker!!:eek: All this testing took place within a 30 minute interval so the test parameters remained consistant ( how long could it take to change a drop-in filter? ). Even when I got the 406 cid Lingenfelter motor Mr. Lingenfelter said to stay with the K&N so this tells me that either he was getting a serious kickback from them or he believed in their filters. I tend to believe the latter. I'd reckon that the filtration is, at the very least, equal to the Lexus filter & more than likely vastly superior. Just clean & re-oil at 50k intervals & the GS will breathe for many miles!!

 

took place during a (single) thirty minute interval so all of the parameters were equal."

Except:

For each suceeding run your tires were slightly warmer and the tire pressure was slightly higher.

Oil temperature, viscosity, friction?

Trials, with, without, should have been "interleaved".

"Control" testing:

How much better were your runs with absolutely NO filter in place?

Recommending K&N by an independent third party that either will benefit from the necessary overhaul or in the alternative clearly will not suffer from the potentially negative financial consequences.

My Lexus service manager recommends that I change out my automatic transmission fluid, differential fluid, anti-freeze, etc, etc. Be weary of anyone so willing to spend, needlessly, YOUR money.

 

I'm with Mean Gene on this one.