My friends and I rebuilt my engine over last thanksgiving break and I changed the oil like every other week up to now... Anyway, I was getting ready to change the oil again when I looked at it and it still looks like a clearish, light brown--like new oil... I was wonder if I kept changing the oil habitually like this, how long can I keep the oil so clean.

 

I change my oil & K&N oil filter faithfully at 1,500 miles. Now on my 2nd RX7 doing so. The oil on the stick is hard to see in direct sun light it is so clean. I admit I am **** and the changes add up $. It certainly can't hurt with pristine oil passing the OMP and lubricating internals.

BTW, change Diff every 12K as well (Redline gear oil) . It too is spotless.

 

Damn dude, that KN filter is 10+ bucks OO

 

Yeah dude, that just rediculous. If the oil is still clean you shouldn't replace it. Remember, oil itself doesn't "break down." The reason you change oil is because it gets contaminated and the additives get used up. Black/contaminated oil still has the same lubrication abilities as clean/clear oil. If the oil is still clear it obviously isn't contaminated enough to warrant a change.

 

Remind me to never take my car to you for service.

Oil does break down, if it didn't, there would be no point in changing it, contaminant issue aside. The cleaner the oil is kept, the better lubricity properties it has, waiting till it is filthy black, to change it, is just palin not caring about your engine and ignorant, as is your post.

 

Yea, I thought that the blacker the oil... the older... the less protection offered... but that is just what I thought...

 

Plus, from what I've been told, the cleaner the oil, the cleaner the engine internally=the longer it'll last...

 

Well, contaminant issues aside, how exactly does oil break down? When you drain the oil from your pan, is it not OIL that comes out (contminants aside)? What exactly are the mechanisms that transform the chain of hydrogens and carbons that constitute oil into something else (and they must become something else, they don't just dissappear)?

What I am saying is that contaminants and the lack of additives are the only reasons you need to change the oil in your car. The oil in your car is made up of chains of hydrogen and carbon that exist, unchanged, from the time you first pour it in, to the time you drain it. If, when you drain your oil, you were somehow capable of removing all the contaminants from the oil, there would be no reason why you couldn't pour that now clean oil right back in.

 

Heh, you said lubricity (The quality or condition of being lubricious)
lubricious: 1. Having a slippery or smooth quality.
2. Shifty or tricky.
3.
1. Lewd; wanton.
2. Sexually stimulating; salacious.

At first I didn't think that was a word haha, I would have said lubricating properties. Just goes to show how smart I am though

And yes, oil does not break down. The additives get used up, and it get contaminated with impurities. That is why you change it. I wish they had cleaners so you could clean it, and ad some additives for the specific brand and re-use it. But I think it everyone changes at a different time, and certain engines use oil additives at different rates, so a set amount of new additives to add could not be done, probabally more work than it's worth though...later

BTW, I think you's jumping the gun here. Dahron said nothing about waiting for oil to be filthy black before changing it, he merely refrenced something to make a point about oils...later

 

On another note, if it's clean, that just means it has few impurities in it. Let's say the oil has over 10,000 miles on it. Would you say the additives are still doing their jobs because the oil is clean? Not speaking of synthetics anyways, lets say for this example that this oil has a recomended change interval of 3500 miles. You know that the recommended change interval is when the manufacturer predicts the additives will be used up in the average engine, right? And the manufacturers ar usually pretty conservative. So... I worry about making sure the oil stays clean, and I can change it at the recommended interval, and still be AJ squared away...later



"Yea, I thought that the blacker the oil... the older... the less protection offered... but that is just what I thought..."

the blacker, the dirtier, could be older(but could just be an engine in bad shape as well), less protection yes, how much good is oil that is all contaminated?


"Plus, from what I've been told, the cleaner the oil, the cleaner the engine internally=the longer it'll last..."

Well, yes, the cleaner the oil, means it's not picking any debris up from anywhere in there, which means it must be in decent operating order in there, therefore it would last longer...later

 

My Oils Purple

 

Mine too, acctually I switched over to the stuff about 6 months ago...later

 

my oil was lookin' like mayonnaise but it's all good now

 

 

The best filter is the oem one, mucn better than K&N. and they are like 5 bucks each....



Laters Gil

 

Boy am I glad I was the first to comment! This is a rip. I totally agree with the logic that claims a really clean oil carries fewer particulates and crap from the internals. Particulates and crap equal friction which equals wear which leads to boo boos. Since I change it ridiculously often I carry not a care about addatives breaking down. Strange no one discussed the possible problems with rotar burning less than clean oil and the reduced carbon build up in seals.

Gildardo, since changing from Mazda OEM filter to K&N, my oil pressure is noticably higher at idle and at 3K.

Here is another testiment to frequent changes. My first 7 bought new in '90 went 228,000 on original engine.

 

PLEASE PLEASE PLEASE, go to www.bobistheoilguy.com and click on their forum links to get an EDUCATION about oil.

You can not visually check the oil. If you want to see how your oil is holding up, then a oil analysis from a lab is required. I analyze my oil at blackstone laboratories for about 30 dollars a sample.

In one of my other cars, the oil turns pitch black in 5 minutes of driving but my last oil analysis showed that I could have gone 12,000 miles on the oil instead of the 10,000 miles I put on the oil.

With that said, I use Haveline 10w-40 in my 91 S5 and my oil change intervals are based on time on engine, not mileage. My vert gets an oil change every 100 hrs on the hobbs meter. Its a very conservative oil change which can vary anywhere from 2,500 up to 5,000 miles depending how much city/highway driving I do.

 

First time I changed mine was after the previous owner had it done at a Mazda dealer. For some reason it was red???? Now it's the nice tan color that 20W-50 Castrol is.

 

And I thank you for your support.

 

my oil is verry clean considering i change it like 2 days ago and i get MAZDA filters for 17$ so dont feel bad about the 10$ KN filters

 

I was wondering... If the 13b injects about a quart of oil every 1000 miles that is burned up - haven't you "changed" the oil when you have put in 5 quarts after 5000 miles? I mean we keep replacing burned up oil with new oil so how could it "breakdown".

Now, I would agree that the filter should be changed at reasonable intervals, but wouldn't we notice a decrease in oil pressure from less flowing oil filters? Is the pressure sensor before the oil filter or after it? Wouldn't the pressure sensor read higher if it was before the clogged filter?(less flow = higher pressure) Where as if the sensor was after the filter it would read lower due to lower flow @ a higher pressure?

Anyway nice thread

Ramses666