Are you talking about the filter or some kit, as I am not aware (short of something customized) that K&N makes any kind of CAI system for the RXs, and most of their stuff is ram air.

 

In the classic car and muscle car world, there was a thread on this where mileage was discussed and K & N filters came up. To give the reader's digest version - "there ain't no free lunch". One of the ways to improve mileage is to improve breathing which means a freer flowing air filter. The gist of the discussion was that K & N gives a freer flowing air filter by allowing more particulate matter through their filtering medium. So, you MAY get a mile or two better fuel economy but probably at the expense of increased internal engine wear.

Just my opinion.

Gary

 

you realize that you can always remove the stock air box then put a round type filter on the end and leave everything else including the stock hose and connectors the same. my mechanic said that just repalceing the filter should not be a reason for a dealer to refuse to work on your car.

 

Gary is right. The net free area determines volume of air. K N allows more air, less media...is it allowing particulates to go through....maybe debatable...but concept is right.

 

the oil from the filter contaminating the MAF sensor. This has been reported as a problem on a BMW forum I frequent. Plus as I have pointed out before unless you install some sort of better exhaust system you can not flow more air effectively if it has no where to go. So, how about a cold air intake AND a set of headers and dual exhaust the whole way back. Unfortunately, I have never seen a performance exhaust or cold air intake for the RX. Anyone else?

 

Todd has a valid point...CAI alone will not add HP, you will maybe like the sound....but Lexus is trying to absorb the noise.....

 

There have been a few independent studies on aftermarket filters and found them all to filter less effectively. In addition, they tend to clog up faster than paper filter.

 

Also the re-charge kit is expensive....I have always stuck with paper filters...

 

I use to use K&N filters, but recently switch to TRD filters. I just replace them every 2 years. They cost twice as much as the OEM paper filter, so its a wash price wise.

 

Where do you purchase the TRD filters?

 

I bought it from Sewell, but its for my other car. I didnt see one there for the RX.

 

the trd filter is like a foam type thing right? if so i'd use an HKS one.

 

No, TRD is the same as K&N. The material is very similar and needs to be oil. The dimension and the plastic housing is diff.

 

The oil compensates for the lesser media....in effect, filtering the same but allowing more flow....