joedaddy1

iTrader: (1)

Can someone check this for me?

at least for the RX400h there is a inner filter in the air duct right after the regular air filter...

it's hard to describe..
basically when you are changing the air filter, can you see a mesh/cloth material right above the new filter (in the air duct)

if not, i figured the 400h has an extra inner filter that we could probably take out for less restricted air flow..

edit: here's a diagram..


in that diagram.. in that box around the filter area, i am talking about the air box behind the filter..
in the 400h, there a full-size, permanent filter in there..

thomas1

I believe that is a environmental filter (Charcoal) I remember something about it is to help with emissions....I may be wrong...

joedaddy1

iTrader: (1)

okay.. sounds like rx330 has it too...

hmmmm.. last generation OEM BMW air filters have it built-in... Aftermarkets don't..
newer generation OEM BMW filters do not have it..

now I am wondering if taking this piece out will yield better power / fuel economy due to the better air flow..

i dont see any "dirtier" air coming in as long as we change the OEM filter regularly?

takeshi74

Try it. Gains will probably be negligible.

spacecraft

+1.
I wouldn't be surprised if you would actually get the opposite result - namely, lower engine efficiency (particularly at low/medium rpm) and worse MPG.
In modern cars, a lot of engineering thought and tests go into the design of air flow.
If just by removing some bits you could get better results, the builder would be the first to do that...

DixieLex

The computer that controls fuel/air mix has basic settings and this throw up a dash board light and could mean a trip to Lexus to get it turned off. Leave well enough alone.

If you want to squeeze a little better economy, try a 0w-20 syn oil or syn ATF

joedaddy1

iTrader: (1)

while I agree with you some what...

I have a feeling that this might be in the way as a way to reduce vibrations?

oh well.. i guess the world will never know....

LEXRX04

yeah your not going to see a noticeable gain when pulling that out..I would just let it be.