I've had the K&N Air Filter installed in my RX for about a month now.
Definitely seeing mileage improvement. Not sure about performance.

I've also started hearing a "whining" sound coming from the engine at about 45-50mph, especially on cold mornings. Is this related? Is this increased airflow? Anybody else get this?

Eph

 

its about a month for me as well, but no complaints. No new noises. The increase is definetely in MPG and not horsepower as far as I can tell. The biggest difference in performance I have found so far without doing any further Mod's is using premium fuel over regular. I swear it feels like a different vehicle when you put down the pedal.

 

No. THe whining noise does not come from the filter. It comes from the transfer cage. You have an AWD right? When it's freezing cold, the oil in the cage is not as viscous. Therefore, there is a sound. After it gets warmed up down there, the sound goes away. You can flush the oil in the cage and put some synthetic but it's a hassle. No worries.

Also, when you start the car in the cold, your rpms should be a lil higher. As a result, the filter should have a noise. It's normal. I used to have an AEM CAI and the noise is loud but sounds nice!

 

TRDHarrier..
Thanks for that note.....I too heard noises in the transmission or transfer case when it is very cold out and I was goign to see if anyone else noticed this. You answered my question...

What type of synthetic do you recommend...I have 75W 90 Mobile 1 and wanted to change these fluids anyway since my 99 RX has 85K. I recently had the tranny fluid changed at Valvoline and it is bothering me...they showed me from their books what they were suppose to put in but after reading more about it I don't like the fluid they used and decided to flush it myself with T-IV. Fluid they took out was black or brown......what is the normal color of T-IV?

 

HOWIENJ

I have noticed the same performance increases in all my vehicles when I put in a higher octane fuel. The problem is the premium is another .20$ a gallon and I really don't notice mpg increases, only slightly more power. What did you experience in the RX?.......The other problem is that with the extra power I tend to use it which kind of defeats any mpg improvement. I just ordered the K&N for all my cars...and all three have computer average mpg readouts....anxious to see if it makes a difference.

 

How much of an improvement is there with the K&N filter??? Im in the market for a new intake and wondering if getting the weapon r intake system would be better then the K&N.

If the K&N improves mpg significantly then id get that but if not then ill go with the weapon r.

 

I'v seen an 8% improvement in gas mileage with the K&N.

Horsepower? When I get another RX 300 as a loaner, it's
clearly more sluggish compared to mine.

 

Where's the best place to order the K&N from and how much?? Thanks.

 

I bought min at Advance Auto, but the best prices I've seen online are here: http://www.ajusa.com

 

It's a Lexus! Put Premium Gas!

 

As many of you may have seen my other posts, I happen to live in Mexico City. Basically, the Lexus needs to be at top specs down here, as Lexus is about 700 miles away in San Antonio and Toyota is your closest friend.

I put in 93 Premium Pemex. If you own a Lexus and use just regular, it is like crying about the high cost of insurance on a Ferrari that you own. I would highly recommend you fill up with Chevron Premium, as it will really clean out your injectors (via Techron). Whenever Costco gets a shipment of Techron down here, it sells out within an hour (luckily I have a friend in the store). I would put in only Toyota Type-IV ATF, and make sure they use a pump when getting rid of the old ATF. I have had some friends with Lexus down here and in Guatemala go with Mobil 1 ATF, and so far no problems.

As far as oil, I have no real good synthetic choice down here but Mobil 1 15W-50. Mobil1 will not sell the lower weights here because they do not perform well at 8,000 foot elevation. I tried this for myself with 5W-30 and 10W-30 I brought from the states, and sure enough they were right, it burned oil like the 2nd Armored Division throught Republican Guard Units. However, the 15W-50 is just about right. For sea level 5W-30 is your best bet. If I were back in the states, I would pop in some more expensive Amsoil.

I also use the K&N air filter and also the oil filter, which has performed very well in trapping the crud and keeping good flow for such a high weight oil. Yet, Toyota's filter (really a Purolator 1) and the Mobil 1 fitler, are good bets, too.

Several months back, I also made the decision to switch my brake fluid to a DOT4 made by Bendix, a subsidiary of Honeywell. Was not too bad, expecially with the Hawk Performance brakes on my fron wheels (you need them here, too many hills and crazy drivers). However, I was not satisfied as there was contamination given the environment here. So, I switched to some Valvoline synthetic brake fluid I brought from the States. WHAT AN IMPROVEMENT! Much better stopping power and no contamination. The constant worry about leaking synthetics has so far proven unfounded.

Turns here in Mexico are nuts. With the terrible turning radius of our beloved RX300s, I just was not getting firm control. So I switched to Valvoline synthetic PS fluid. Much better control, and and now I can make the high speed turns I have always dreamed about with ease. Again, no leaking thus far, and a recent Lexus inspection revelead no problems with any of the seals or system (I asked).

By the way, if your ATF fluid was black or brown, I have got bad news for you, change it. I recently told the horror story on the Maintenance Board about a friend of mine with an ES300 here. Toyota put in the wrong type of ATF (ESSO regular), and the transmission fluid burned to a crisp after about 80 miles. Had to have the whole car towed back to San Antonio. ATF is not something to neglect.

 

8% increase in gas mileage is accurate as Daddy-O states above. Mine went from 21.6 on highway to 23.3 which is exactly 8%. I only have 4500 miles on my 2002 and didnt get on the premium kick until recently. Still learning a lot. I actually leased the RX the end of last august but my Durango lease didnt end til mid January.

Lexus was really in the mood to move the Millenium Silver they had on the lot quickly with the "03 coming out the month after and the 330 only 9 months away. They not only gave me a lease deal of $50 less than any I had seen previously but they gave me $2000 in some sort of funny dealer coupons that went directly to Chrylser to pay off the last 5 months on the Durango.

I had the Durango free and clear from the end of August til Mid January with only 30,000 miles on it. Killed myself trying to put on the last 6,000 miles. Went to Canada and did as much as I could short of driving to Florida. Ended up giving it back with 34,600 miles on it. A waste of 1400 miles but, the RX sat in the Driveway for about 5 months barely touched. Had only 1200 miles on it when I gave back the Durango.

Definitely go for the premium fuel. Dodge recommeded using only 87 octane in the 4.7 magnum engine, premium was bad for it, so beleive me paying the extra .20 a gallon did bother me at first. After leaving an 8 cylinder Durango, the 3.0 6 cyl didnt thrill me originally. Switching to the K&N airfilter and using 93 octane did the trick.

Well worth the $4 extra per tank full.

 

Howie,

When you put in the K&N, did you disconnect the battery to reset the computer?? I'm thinking of ordering the K&N for my '02 White Gold Pearl this weekend. I've got 13,500 miles on it now. Thanks for the good info.

Love the K&N in our '97 Expedition.

 

I did disconnect the battery cables. However, the first time I did it for about 20 minutes and the only thing that reset inside the truck was the clock. I figured I didnt leave them diconnected long enough so I did it again. This time for an hour and the entire computer reset including the clock and radio presets.
I guess that was long enough. I do know that some people have disconected both cables and touched them together for an instant reset. I didnt have the guts or the desire to find out what happens when you do that so I waited the hour instead. I have also read that if you dont disconnect anything, the computer figures out that there is a change in air flow anyway after driving for a while.