ever use K&N 33-2329 High Performance Replacement Air Filte

When cars had carburetors, K&N was a good idea. Be careful not to get the oil on your MAF sensor.

 

I use only Toyota parts.

 

At best, it'll do nothing. At worst, you could oil it wrong, cause restriction. It's snake oil.

 

I remember my son went shopping with one of his automotive inclined buddy, came home with a K&N filter for his car. At the time I thought: oh yeah...

He stuck with it for a while. But it's really a hassle, a solution in search of a problem.

 

Using oiled air filter with any car that has MAF-sensor isn’t good idea. And Prius has had problems with MAF-sensor even without air filter oil so no need to make it worse.

 

Been using one for hundreds of thousands of miles. Guess how many air filters ive bought for the car since I bought the k&n. None. It costs 3 times the price of a good filter (wix) but you never have to buy another filter.

 

Ditto. I've used k&n for hundreds of thousands of miles across many different cars. I noticed nothing in terms of performance or fuel economy. I continue to use one because its the only filter I will ever have to buy for the car. Cleaning and oiling it is a pain. But it's a much bigger pain extracting money from my wallet and adding trash to a landfill. I use a cleanable air filter in my home for the same reasons.

 

Plus, the MAF isn't hard to take out and clean. I would clean it every time you clean the filter.

 

Its called MARKETING!
"Our automotive OE (original equipment) replacement air filters generally add 1-4 horsepower." LINK
All that money for 1-4 horses. Oooooooooooo. Ahhhhhhhh. Ohhhhhhhhhh.


Read this in its entirety (its not long). Its an objective, and scientific test performed on nine air filters, one being a K&N.
http://www.nicoclub.com/archives/kn-vs-oem-filter.html

"However, if a filter is using “better airflow” as their marketing tool, remember this….Does it flow better? At very high airflow volumes, probably. BUT, our engines CAN’T flow that much air unless super-modified, so what is the point? 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 be recognizeable. At that point performance will decline somewhat. Replace the filter and get on with it."​

The factory engine is a balanced system (a compromise of performance, reliability, and efficiency). Air filter all the way to the exhaust, don't forget the ECU programming. Add a K&N filter, the system is unbalanced. To maximize the potential, additional air flow increase K&N can offer, one would have to change out many other parts; exhaust system for sure, as the stock exhaust is very restrictive compared to a "performance/racing" exhaust systems.

I previously assumed Formula 1, NASCAR, and Rally cars, were using K&N or something comparable. A recent Internet search only revealed NASCAR, since 1-25-2011, LINK. Corporate sponsorship has nothing to do with this. Unfortunately, found no information about air filter type used on F1 and Rally cars.

We are driving a Prius. Not a sexy car, nor a fast car, but sexy MPG.

If you did not read the nicoclub link above, here's a graphic teaser:
Filter Efficiency (How well does the filter capture debris.)


Accumulative Gain (Total amount of dirt that passed through the filter.)


These two graphs speak volumes. If you logically think about K&N's premise: increase Horse Power by increasing air flow. The less restrictive the air filter, the greater the air flow. Unfortunately, more debris will be passing through the air filter (as shown above), into the intake manifold, then into the cylinders. Even if no cars are ever damaged running K&N air filters, is the cost of the filter, filter oil & cleaner, and required maintenance of these filters require, worth the 1-4 Horse Power increase?

Most of us are probably changing the air filter prematurely. An interesting report by the EPA on clogged air filters and the impact on MPG, concluded

"Closed-loop control in modern fuel injected vehicle applications is sophisticated enough to keep a clogged air filter from affecting the vehicle fuel economy."​

LINK to the EPA study (2-2009).

 

If you're an eco-nerd with some good math skills you can probably make a case for using an oily cotton filter to substitute a dry paper one.
There's probably an economic advantage as well if you keep your car long enough, but it's the same type of economic (and ecologic) advantage as keeping the oil in the motor for 10,000 miles instead of five.

If you do your own maintenance you can usually get by with both. I'm capable of removing and cleaning the TB and the MAFS on my vehicles, and it's not hard at all.

Having said allllllllll of that, I like the convenience of popping a paper filter into my car and not having to buy cleaning kits.
I have no problem with K$N filters until you get to the part where they claim to make your vehicle more fuel efficient or turn it into a fire-breathing, tire smoking track monster.

Then?
You swerve right into snake-oil territory.

IMHO in an OEM Prius, the filter makes no additional horsepower, and saves no additional fuel.

If they saved a meaningful amount of fuel, CAFE regulations would almost mandate their use.
If they generated a statistically meaningful amount of additional BHP don't you think that a vehicle like an SRT Hellcat would install them at the factory and bump the BHP up to an even 725???

There's a reason that these filter types aren't used by the OEMs.

 

I remember using those K&N filters way back. Having to clean and oil was a hassle compared to popping a new one in. After a couple washes, when I held the K&N to the sun, I can see tons of small holes going through. Tossed garbage into garbage.

 

Use only Toyota parts. That is the safe course.