TunedRX300

There are UOAs for ATF, coolant, and gear fluid.
http://theoildrop.server101.com/foru...=0&Board=UBB50
It is not how one sleeps better, it is obtaining information in a cost effective way. Also it helps to know what UOA does. If you read the link I provided above, you will not put gas in the list.

jednav

It is amazing how some people hold their vehicles so sacred, with the belief that it was made perfect. Am all for preventive maintenance but some measures taken are extreme, and just marketed to satisfy this dillusionary sense for profit taking.

These are the same people who fears being outdone by its neighbours, and will up the ante by buying the latest and greatest vehicles. Meanwhile, their properly tuned vehicle looks outdated, sad and ugly, and ready for the junkyard.

TunedRX300

Not necessary, $20 is a cheap way to do a health check on expensive items such as engine and tranny. I would not worry about gear, brake since they are cheaper. Have you checked out Lexus' pricing of labor and part for engine and tranny replacement?
Also don't assume motivations from those who have done it. Some used UOA to optimize oil change interval safely. Check out previous posts, many would not feel safe go beyond 5K. I was also not willing go for longer with a Group III synthetic oil, even though owner's manual indicates 7.5K is the interval for normal driving. For my Acura, I used to change >$30 worth of oil and filter @ 5K, but now a customized UOA and professional analysis provides me valuable information to reach 7.5 ~ 10K. In my case, I come out ahead after my 2nd DIY oil change. That is $ and time saved, well worth the $20.
For 1mz-fe engines in RX300/ES300, 5K interval on Group II mineral oil is not sufficient, many UOAs showed oil have depleted acid neutralization additives long before 5K is reached. ES330/RX330 3mz-fe also exhibit similar harshness on oil, 30 weight oil became 20 weight at the end of oil change. But again, how does one know the Ph balance and viscosity had he not done/seen an oil analysis?
Again, it is a personal decision. There is no right or wrong.

T0ked

iTrader: (2)

A little extra effort helps save you money, keeps your car well maintained and preserves natural resources. How much oil will we waste if everyone just blindly did a 3k/3mos oil change? I've gone from 4 oil changes a year to 2 and the oil analysis shows me that it is very safe for my engine, that I'm not doing anything detrimental. For me this was a win-win situation. Every little bit helps. I've also saved way more than that initial $20 outlay for the analysis at this point. Every engine is different depending on how it had been broken in and used. The manufacturer guidline is just that a guidline. You can always fine tune it to your needs. Some might say that blindly following an outdated requirement of 3k/3mos is another example of profit taking, by the ol companies, and we all know how much profits they need... As usual, there are some people who become obsesssed and do many UOAs. It becomes a hobby or something more. But you'll find that with everything. When used properly, an oil analysis will help save you money and keep your car running well. I don't see a wrong in there at all.

Russ G

I change mine when I hear loud scraping noises coming from the engine bay. How do you open the hood on these cars? OK, maybe not that long. I'm between 5,000 and 7,500 miles. Always filter and dino. It really depends how cold it is here in Chicago. I don't crawl on my back when under 45 degree F. I do check the oil almost every fuel fill so I make certain that it looks fresh that way also. I use the Maintenance reminders to make certain that I don't forget.

geko29

I go about 16k on my BMW (mfr/OBC recommendation), and my UOA tells me that's just fine--in fact they said it didn't need to be changed! I'm hoping to extend the interval in the RX to 10k (I doubt the sump is deep enough to support 15k), and will use UOAs to make sure that's safe. If it's not, I'll stick with the recommended 5k interval. 3k is just silly nowadays, unless you're taking used oil out of one car and pouring it through cheesecloth directly into another.

mitsuguy

iTrader: (2)

BMW's have twice as much oil in them... If you were to up the oil capacity to 20 quarts, you could probably go 30k miles or more... the oil is used less frequently, and any dilution or contamination is lessened because there is so much oil to go through...

geko29

Yeah I figured as much. My BMW takes 7 qts for a 2.5L I-6, while the RX takes just over 6qts for a 3.5L V-6, which is why I wouldn't expect to be able to go 15k on the Lex. 7.5k shouldn't be a problem, and even 10k might be doable, but the UOAs will tell me for sure.

MeehSoFly

1year 8,000 miles?? are you kidding me?? ahahaha....by that time I guess you might as well buy a new car. just change it every 3,000 miles. I guess you're a newbie driver huh? but anywayz..goodluck.

kingofire

Reading your comments, it would lead me to believe you are the "newbie driver" If you dont know facts please dont criticize others who seek help. FYI, I can easily go 5,000 miles on conventional oil and go 10,000 miles on synthetic oil. If i didnt have to worry about warranty, I would be doing 8,000miles/1 year oil changes with synthetic oil! These ARE facts since i have UOA's to back up my claims! As for you, I would do more research rather givefalse information to people seeking help!

GSteg

iTrader: (15)

the 3000 mile rule doesn't really apply to most newer cars anymore, unless you drive your car very aggressively. Newer cars are built better than they were two decades ago. It's not uncommon to see conventional oil lasting more than 4000 miles. Not to mention, 3k interval may be "ideal" for dealers so that you can take your car in more often.

tmf2004

iTrader: (15)

Mobil 1 every 3k.. I think i have changed the oil a few times since i've had the car.. which has only been two years and very very low mileage.. (will not disclose) LOL Yea every 3k..

pingu

At least twice a year. I have started to drive my GS on a daily basis. I think I went 4500 miles before an oil change only because I was busy during the time (finals). On my 240z with carbs I change her at 3k or twice a year.

jshooter55

i don't use synthetic i use regular castrol syntec... should i change to synthetic? i have 187,000 miles on my 94 GS300... But i haven't had any problems...

geko29

With that many miles, switching to synthetic is probably not wise. Reason being, you likely have some small oil leaks currently plugged by sludge and large oil molecules.

Put synthetic in, and the detergent package will eat the sludge, then the tiny synthetic oil molecules will seep out the holes. Generally if you're going to make the switch, you want to do it early (first 50k or so).