Will i get a better fuel mileage and how much ???

 

Not much to be excited about, but it is the ease of cleaning that helps. Helps the engine to breathe easier.

 

it should help with gas mileage, probably not much, plus you wont have to keep buying those paper air filters. before the boring police jump into this thread, dismantling your stock air box and putting a KN air filter will make the engine a bit louder plus you'll hear a slight hissing sound. But since the rx is so well built that shouldnt matter.

 

The K & N claims the engine will breathe better (takes in more air). The engines senses more air and will increase the fuel to maintain the correct air/fuel mixture. So my guess is that it might decrease fuel economy but you might have slightly more power.

 

The main reason i'm thinking about filter is that i have warranty and not looking for any bs from dealer if i install intake otherwise i would get an intake.

 

My experience with it in my RX300 (when I had a stock airbox) was a little ambiguous at first. The issue I had was the oil was coating the red diode on the MAF sensor and causing a P0171 (most common OBDII error in an RX300). Trick was to clean the diode and then pull the EFI fuse to reset the CEL (for lack of an OBDII sensor at the time).

What I did later was to rinse the oil of the filter and just coat the side facing the airflow. Less of an issue then.

 

i dont think the dealer will care as long as its properly installed. KN filters usually have a CARB number, so if the dealer bugs you just show it to them.

 

K&N drop in filter does nothing for power and MPG. I had K&N filters in my 5 cars. Any power gain you might feel may be due to the fact that it is a new air filter. I use K&N because it last longer not because it performs better. If you cahnge your paper filter every 12 months, it will perfoem just as well. I just switch out my K&N filter for a TRD filter. The TRD is better built and has more surface area.

 

What's special about a TRD filter?

 

uh the factory air box is very restrictive, if you switch to a KN filter that will help the car breathe better then the stock filter. im talking about the round type, where you get rid of the stock air box.

 

Cold Air Intake (CAI) you mean? This will be a red flag with the dealer for warranty, if your car is still under warranty.

 

Plus CAI will make your GX louder, I like a nice quiet ride, thats why I bought a Lexus.

The TRD has a better rubber housing and has more filtering surface area, cost about the same.

 

CAI noise doesn't bother me much but dealer not fixing something will .

 

What CAIs are you referring to, custom or some brand name?

 

K N Cold air intake