I know many people argue about installing a K&N style filter is better than a stock filter. I have no arguments about that of which is better or which is better air flow (air flow being the key subject). K&N are nice, I do have one in my GX470 due to the amount of off-roading I do with it. Just clean and reuse. But before you go too deep thinking about better air flow; look in your air box and you will notice a stock carbon filter on the top unit that is not replaceable. This unit is major air restriction.

I am just giving everyone a tip to try, if you don't like the idea then simply don't do it. I believe this carbon filter is for gas vapors leaking back into the air. I do have emissions by me and all of my vehicles and my friends vehicles we done this on have had no issues from emission tests or engine lights. We have done this on Toyota, Scion, and Lexus vehicles. I have done this on my 2007 GX470 at 79K and now has 138K and never had an issue. My 2009 LS460 is where the pic's are from and did it 6 months ago with no issues. LS is using OEM style filters, GX has K&N. NOTE** if you use K&N careful on the amount of oil so you do not get the MAF sensor full of oil, without this filter you might get excess oil on sensor (I oil and let it set for a few days, dampen off with towel before installing).

Steps: (sorry I was not able to type by pic's)

First pic is the filter on the top air box. Remove from car and set on the bench.

You will find little melted rivets that attach the filter. I used a razor blade and cut the edges off. Take a small flat screw driver and gently pry up. Be cautious so you do not damage the box edge that seals to the bottom box, do not worry about the carbon filter you are removing.

You can now see how much air flow this filter restricts. Now put top box back on, save filter to make you feel better if something happens. Repeat for other air filter box.

 

Good idea! I wondered about those when I was getting acquainted with the 2011 LS. I haven't seen them before, my previous car was a GS 400. A definite restriction. Can you hear or feel any difference?

 

And do you notice any improvements in power or fuel economy? Or loss of fuel economy? Or is it not noticeable in either department?

 

My GX did get about 1mpg but when I have mud tires on and my heavy foot hard to talk mpg improvement. Now power, I did add the K&N at the same time but I will say the hp and torque did increase a lot. I noticed this while hill climbing and playing in mud.
My LS I did see about 2-4 mpg on hwy. I do get 28mpg strictly hwy if I drive nice and stay at 70mph. This is hard to do as people usually **** me off and I hit 100 mph to get away from them.
Overall this mod will get air faster into the intake. But remember, the MAF sensor with throttle position controls the amount of air/fuel mixture into the cylinders. This is great for instant power increase and overall easy flow. It is a free mod.
If you want better mpg start with tires. You want HP then expensive mods starting with computer mods but hard to find for these toys.

 

If you run a K&N filter, you are wearing your piston ring lands and rings out prematurely. This is because K&N filters are less restrictive - good for power, but bad for your engine. They let small grit particles in, which are easily felt on the inside of the clean air tube connecting to the throttle body. You can see right through the K&N's filter gauze, which means particles of dirt that size can and do get through. Sorry to burst your bubble, but they are bad news for engine longevity.

 

My past experience with K&N filters were terrible. This filter damaged my Mass Airflow Sensor (MAF) in my BMW by allowing in too much oil. I didn't see any gains, either. Not worth the time and trouble, IMHO.

Another classic case of trying your luck by underestimating the Lexus engineers who built the car and believing you know more than they do. It's your money and your time. Just sharing my pain with you.

/shrugs

 

Hmmm. Never had issues with K&N and I find it hard to believe that they allow particles past versus OEM that would catch. Assuming proper installation...

 

http://www.nicoclub.com/archives/kn-vs-oem-filter.html

 

I've seen other tests that showed similar results, it's why I'm afraid to use a K&N air filter...it's not something I'm willing to risk. The only reason why I considered them in the first place was to save money over the long haul...the whole, you'll never have to buy another air filter thing. I drive 30k miles a year, so it was slightly intriguing, but even then when you add the cost ($55x2) plus the yearly cleaning and treatment solutions...how much am I actually saving? I bought air filters at Walmart last year for $12 bucks a piece.

 

What I'm quickly finding out is that switching to a 5w30 oil really does affect your gas mileage. I bumped up the oil viscosity a bit because of concerns regarding protection and I can't the fuel economy I was getting before. It's not a huge difference or anything, but it is different and it's noticeable.

I'm now convinced that manufacturers went to these light weight oils for one reason and one reason only...fuel economy and the squeeze the CAFE regulations gave to manufacturers. Because the light weight oils accomplish what they're intended for...to push the vehicle a couple mpg extra in fuel economy.

 

It's like buying solar panels for your house. But that's another story.

 

OE filters are only $40/pair:

And 0W synthetic oils will reduce engine wear vs. 5W, because your oil filter will close its bypass valve (and start filtering your oil) sooner after a cold start. Even 0W oils are too thick when cold. Once the engine is at operating temperature, 0W, 5W, and 10W oils all have the same viscosity. The 0W oils just thicken less when cooled. More info on this: http://www.bobistheoilguy.com/motor-oil-102/

 

I understand the cold start aspect of a 0w oil, I'm more concerned with the 20 part of it. The part that is flowing when it's warm. There are many techs that won't use the 20 weight oils. I was at a euro car repair facility and the guy who owns it won't sell it even if he's working on a Toyota. He thinks it's too thin, that it doesn't protect your engine as well, even though it does help with fuel economy.

 

There's many tests that've been conducted on K&N's with startling results. Google is your friend here.

On a personal experience, I was using K&N in my 02 Ford F350. After sending in my oil sample to Blackstone, my report commented on an unusually high silicate level. Silicate of course, is SAND. Needless to say, that's not good. Out came the K&N and back in went the paper filter. I don't need to save 20 bucks every two years on a filter for essentially ZERO performance increase.

 

They would HAVE to let more particles through because they "allow more airflow". You can't have it both ways. More air = more particulate matter. Add to this the common problem of over-oiling the filter (which screws with your MAF sensors), or under-oiling, and one quickly realizes that these filters are more trouble than they're worth.