Is A K&n Air Filter A Good Idea In The Rx300?

[bartkat]

How about 15whp, just K&N drop in without the arm? Are you a believer?

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On what car?

[92Lex]

Well do whatever makes you happy RX400h. If you believe that dropping in a K&N will give you substantial gains then do that.

Every company is going to try to sell you into their product regardless of if it works or not. This topic started out as "K&N air filter a good idea in the Rx300?", I'm here trying to word my opinion while trying to keep it Lexus related.

Prior to owning my current vehicle I was heavily involved in the import scene. Trust me, an air filter alone will not do you any good...dyno proven.

If you want to know why it damages MAF sensors then do a search. If you don't care then hey, what can I do about it?

On RX's barkat.

[TunedRX300]

Every company is going to try to sell you into their product regardless of if it works or not.

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K&N is not alone, Lexus and other automakers have been using their marketing machines for years to sell not only cars but also OEM parts. Lexus has a much easier time to sell since the car is a nice entry point for selling more services and parts. Those who use an aftermarket products must have a compelling reason to switch. IMO, it is an individual decision.

[RX400h]

92Lex,

I have been using a Halltech Stinger-R intake for many months now. Its oiled filter has more surface area than any other filter on the market (at least for Corvettes). I have had no issues whatsoever. I also have two other vehicles that use K&N filters. Neither have had any drivability problems due to filter oil. They key is to re-oil lightly. It is true that if you over-oil, you will have MAF issues. Fortunately, many MAFs are easily cleaned with contact solvent.

Dave

[bartkat]

Let's face it guys, all intakes and filters suck.

[jgr7]

I can't help but thinking that Toyota has put much time and money into R&D for these engines. To think that K&N is going to make a drop in that will make the Toyota perform that much better just seems off to me. Most modern VVT engines as well as others have been tuned to perfection by the engineers. These guys don't build an engine and say well thats close enough lets let K&N finish the job.

I think that it takes at least a 15 HP increase to give you a seat of the pants indication of more power. I've seen guys try to put a new throttle body on a car that can't use all the air it gets now and lose power. If you want more power you have to spend $$$. Pull off the heads and open them up , different cams new throttle body, new intake, then the new air intake and exhaust. Now you will have some HP if you can get the computer to work with all these mods, which you most likely will not. If you are trying to get better gas mileage well good luck, if your like me I love the sound of full throttle and there goes the MPG straight down the crapper LOL. So have fun putting stuff on your car, thats what is fun about owning a car. Just don't have to high of expectations.

[TunedRX300]

I can't help but thinking that Toyota has put much time and money into R&D for these engines.  To think that K&N is going to make a drop in that will make the Toyota perform that much better just seems off to me. Most modern VVT engines as well as others have been tuned to perfection by the engineers. These guys don't build an engine and say well thats close enough lets let K&N finish the job.

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If this is true, why there are so many complains about RX's transmission? An automaker such as Toyota is in the business of making money: cost of goods sold, operational expense, capital expenditure(R&D), warranty liability are as important as selling price and quality.

[jgr7]

If this is true, why there are so many complains about RX's transmission? An automaker such as Toyota is in the business of making money: cost of goods sold, operational expense, capital expenditure(R&D), warranty liability are as important as selling price and quality.

TunedRX300

I'm not sure what transmissions have to do with K&N filters and increased performance.

Yes Toyota is in business to make money that is why the make such a quality product. If all those Transmissions are bad then they would be up the creek with out a paddle, just how many is "so many" I can't even find any numbers. I'm sure that there are bad transmissions out there but what is the % to the number of this type transmission. It does suck to have gotten one of the bad ones, but I see these cars every where I go and if the transmissions were that bad people wouldn't buy them. Jeff

[bartkat]

Performance is compromised by meeting emissions regulations, and somwhat of a demand for half decent gas mileage. Smoothness and quietness are also in demand by most buyers. Engineering is further compromised by manufacturing techniques, and many other factors. Performance is by no means optimized on the average, everyday automobile as it comes from the factory.

[92Lex]

92Lex,

I have been using a Halltech Stinger-R intake for many months now. Its oiled filter has more surface area than any other filter on the market (at least for Corvettes). I have had no issues whatsoever. I also have two other vehicles that use K&N filters. Neither have had any drivability problems due to filter oil. They key is to re-oil lightly. It is true that if you over-oil, you will have MAF issues. Fortunately, many MAFs are easily cleaned with contact solvent.

Dave

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Okay.

[jgr7]

bartkat that is true on the mid and low end cars that compete for high mileage etc. but we are talking about high end fairly high HP VVT engines that were designed for racing. I don't know about yours but my RX only gets about 20 mpg, not exactly high mileage. My Eldorado got 22 mpg with the same driving except I used to do a lot of WOT with the caddy getting on the freeway. Love the sound of that Northstar engine.

I'm sure that in racing applications you will be able to squeeze out more HP but were talking about a stock engine in a Lexus. Most of the HP gained with air cleaner/filter mods are only seen at WOT. Not your average driving style I hope. I really don't think that the air cleaner/filter has anything to do with emissions either. It is there to protect the engine thats all. The EPA could care less if our expensive engines wear out faster from dirt getting sucked into the intake.

Jeff

[92Lex]

An extremely dirty air filter will cause an increase in CO because there will be a lack of O2 to help oxidize the CO into CO2.

You're right jgr7, the EPA doesn't give a shtt.

Performance is somewhat compromised because they are trying to meet emission regulations. They have to juggle to keep NOx, HC and CO down and this leads to a slightly less efficient engine (performance wise). If they were able to have it however they wanted, you would see high NOx and high CO in most of our vehicles. They would also just vent all the gases to the atmosphere, instead of directing it back into the combustion process.

[bartkat]

bartkat that is true on the mid and low end cars that compete for high mileage etc. but we are talking about high end fairly high HP VVT engines that were designed for racing. I don't know about yours but my RX only gets about 20 mpg, not exactly high mileage. My Eldorado got 22 mpg with the same driving except I used to do a lot of WOT with the caddy getting on the freeway. Love the sound of that Northstar engine.

I'm sure that in racing applications you will be able to squeeze out more HP but were talking about a stock engine in a Lexus. Most of the HP gained with air cleaner/filter mods are only seen at WOT. Not your average driving style I hope. I really don't think that the air cleaner/filter has anything to do with emissions either. It is there to protect the engine thats all. The EPA could care less if our expensive engines wear out faster from dirt getting sucked into the intake.

Jeff

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1. All manufacturers, luxury or not must meed CAFE standards. If you look at the RX 300 EPA estimated gas mileage goes from 20 in 1999 to 26 for the 2004 models. So even the big boys have to do something to make their fleet average mileage meet CAFE.

2. RX 300 is an SUV with a tall profile, and a CD higher than a sedan. Part of the mieage problem is going to be wind drag at speeds above 55 MPH. However, your 20 MPG is much better than a comparable SUV from the late 1980's, which were lucky to get 16-18 MPG highway average.

3. You can holler all you want about dirt in the engine, but all other things being equal, a more deeply pleated and layered aftermarket filter will allow better air flow and clean just as well for a longer time period than a stock filter of the same porosity, but less layers and less overall area.

4. Oil on the MAF is moot. If the filter is cleaned and oiled properly, that's just not gonna happen.

5. You have EGR, an air pump, a catalytic converter system, an ECU that tries to keep emissions low, and more that all works in conjunction to keep emissions down. Even with an aftermarket intake, you still hook up the EGR reabreather hose and the gas tank vapor canister hose, so there's no chages made to emissions controls.

6. VVT? Why did they come up with that? It's so the engine can run with low emissions at normal loads, but still give some increase in performance whan you mash down on the throttle, that's all.

7. If the engineers didn't have to worry about any of the above and wished to sacrifice a little smoothness, they'd be pumping out 3 liter engines with 300 HP, and that would be more "optimized" performance, right off the assembly line and into a showroom near you.

[jgr7]

bartkat, I'm not hollering about dirt in my engines I use a paper filter and change it once in a while. The debate is about the type of filter. K&N filter alone isn't going to increase anything enough to talk about so have fun with your mods just don't expect too much. Thats all I'm saying.

The VVT engine will help with emmisions but is really to give a broader power range to an engine which will lead to better fuel economy as well as fewer emmisions. Here is a link from Toyota on VVT.

http://www.toyota-europe.com/technology/gl...gloss_vvti.html

[bartkat]

bartkat, I'm not hollering about dirt in my engines I use a paper filter and change it once in a while. The debate is about the type of filter. K&N filter alone isn't going to increase anything enough to talk about so have fun with your mods just don't expect too much. Thats all I'm saying.

The VVT engine will help with emmisions but is really to give a broader power range to an engine which will lead to better fuel economy as well as fewer emmisions. Here is a link from Toyota on VVT.

http://www.toyota-europe.com/technology/gl...gloss_vvti.html

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Jgr7

The EPA could care less if our expensive engines wear out faster from dirt getting sucked into the intake.

bartkat

6. VVT? Why did they come up with that? It's so the engine can run with low emissions at normal loads, but still give some increase in performance whan you mash down on the throttle, that's all.

[jgr7]

[RX400h]

Performance is compromised by meeting emissions regulations, and somwhat of a demand for half decent gas mileage.  Smoothness and quietness are also in demand by most buyers.  Engineering is further compromised by manufacturing techniques, and many other factors.  Performance  is by no means optimized on the average, everyday automobile as it comes from the factory.

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I agree 100%

[TunedRX300]

TunedRX300

I'm not sure what transmissions have to do with K&N filters and increased performance.

Yes Toyota is in business to make money that is why the make such a quality product. If all those Transmissions are bad then they would be up the creek with out a paddle, just how many is "so many" I can't even find any numbers. I'm sure that there are bad transmissions out there but what is the % to the number of this type transmission. It does suck to have gotten one of the bad ones, but I see these cars every where I go and if the transmissions were that bad people wouldn't buy them. Jeff

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There are other factors determine the design of a product, not just quality and performance. Tranny problem is just an example of Toyota's design is not perfect despite Toyota's R&D effort.