Re: DIY Oil change in a 2002 Subaru Forester?

Why numbers? What about oil itself.

I think the belief that all oils are essentially the same or similar in quality is total crap. There are some really bad oils out there! Most brand name oils are fine, but some little known brands can be really, I mean really bad.

When I change oil I usually collect it in transparent 1 gallon containers (old windshield-fluid plastic bottles). It sits in the garage for several months until I collect several gallons and dispose them together at my local Kragen store.

I have noticed that old oil after sitting for several weeks in these containers has a tendency to separate, that is, thick goo accumulates at the bottom while upper layer consists of less viscous but also extremely dirty old oil. This is normal, but the rate/speed and magnitude at which the separation occurs tells me something about the oils quality- its ability to keep junk in suspension.

Recently, I bought the cheapest oil at Walmart, 69cents per quart

-black containers, I forget the name, some no name brand essentially. After making around 2000 miles on it and draining the stuff and letting it sit in the plastic container for several weeks I noticed something very unusual. The oil separated into to two distinct layers. Bottom 2/3 -rd layer was black and dirty, but the top 1/3rd layer became completely translucent as if the oil was brand new!

I think that were I to skim the top layer and refill the original oil bottles I could return it to Walmart and claim it was unused, and perhaps even get a refund :))))))

The thing was completely translucent, as if it never spent a minute in the engine! Good oil has the ability to keep dirt in suspension for very long periods of time. Bad oil does what this oil did, that is completely separated after several weeks only.

My advice is to avoid no name brand cheap oils. Although these supposedly pass the grade for oil specifications they can be inferior. Better stick with brand name products.

M.J.

Correction: Bottom 1/3 rd was dirty, top 2/3 rd became transparent and clean.

M.J.

Great replies, and thank you all!!

Makes me think that the best products are the ones I can get cool, Nascar-like stickers free with purchase, along with $6.95 shipping and handling!!

But seriously, I don't want to say money's no object, and I'm soley concerned with putting the "best" stuff in my cars (owns a 95 Honda Accord that just turned 100, 000). As it is now, the oil change places charge a minumum 20 bucks to start, which easliy covers the cost of oil and filter.

Maybe I feel more comfortable buying "name-brand" stuff. I wouldn't think to put the "cheap stuff" in my car. It's got to be cheap for a reason, and cheap is easy to make just that. For some reason, I don't think I'd go to Wal-Mart either, to buy their oil. I'd probably buy the Penzoil stuff on the shelf right next to it, but I can't tell ya why.....

So, maybe the eternal question will always be, what's the best?? Twenty bucks, easliy buys ya the expensive stuff, and not counting your time, and changing your oil every 3000 mile or so, we're talking $.00666 cents a mile....

Seems like pretty cheap insurance to me, or at least a little peace of mind....

Thoughts??

DJ (not related to Ricky Bobbie..)

since I don't recall it being mentioned in this thread - more reading and links to analysis,a forum, etc. can be found here;

fyi

Carl

The other oils that I use are Shell Rotella 15-40, Mobil 1 15-50 and 10-30, and occasionally Valvoline straight 50 racing oil- these are the reference group against which I was comparing.

None of these has ever separated like I've decribed, no matter how long they've sat in the containers. I've had instances where oil would sit for nearly a year, or more (I don;t keep a record of this)- still no separation.

My take on this is that some oils are definetely better than others. The no name thing from Walmart is got to be _relatively_ much worse. Whether it is still acceptable for the engine, and whether it makes a big difference for engine longevity, etc.,... that I just don't know. I suspect it does.

I drive a Subaru Impreza '00 (35k miles), Chevy Corsica '89 (178k miles) and Hyundai Excel '90 (85k miles), all of which I am the original owner. I bought the cheap oil from Walmart for the old Corsica as it is aging and has little life left in it. After what I've experienced I'll keep feeding it Shell Rotella and Valvoline like I used to till the thing expires.

M.J.

Hi,

Methinks thou needest to find the nearest oil recycling center, and hie thee to it more frequently if you have the stuff sitting around to look at for such a long time!

I guess now I'm gonna have to search the API, ILSAC, SAE and any other specs I can get a hold of to see if I can find a "sits on shelf for a year after use" spec! :D

In the mean time, have fun with your old oil...

Oh, BTW, that "no name" Wal-Mart stuff has frequently been acknowledged to be Quaker State in the past (could also be Pennzoil since they're now the same company.) IIRC, they were the first mfr to offer a 250k mile "no oil related failure" warranty on their oil. Sure, it was a marketing gimmick, but the fact they're willing to stick their necks out says something about how likely oil related failures really ARE (not!) So I'll venture a guess your old car will do just fine on Wally's "no name" stuff.

Rick

Just to clarify, the 69 cents cheapo oil was from Walmart (bought at Walmart) but was not the Walmart generic brand found in blueish color bottles. It was some no name brand packaged in black color quarter bottles. They have it in several weights 10-40 was what I used.

You keep making fun of my observations but I think that there is some merit to them, that is they tell how good an oil additive package is at keeping dirt particles in suspension.

If you trade-in your car every couple of years this whole issue of oil is moot, but if you keep your cars for very long then such post-mortem analysis on old oil may be of some value (?). Most people dump their oil right away, I because I am lazy and hate getting my hands dirty, happen to store oil for prolonged periods of time. I think this gave me a somewhat unique perspective, I believe, is worth sharing with others.

M.J.

Hi,

Actually that "no-name" oil may prove to be more enviromentally friendly than the "better" ones. Why? You can siphon off the "clean oil" from the top and reuse it, thereby reducing the amount of "dirty" oil to be recycled. Gravity has done a better job for you than your filter!

Think I'm pulling your leg? Send a bit in for a professional oil analysis and see what they have to say. I wouldn't be a bit surprised if the report comes back much better than you think! Of course, you can also just buy a LOT of 69 cent oil for the price of the lab test... and never really know, eh?

Actually, I "plan" to run any of my cars a minimum of 200k miles. Sometimes that doesn't happen, other times I exceed it by quite a bit. I change my oil at regular intervals, take it to the recycling tank without really "looking at it", and I'm done with it. It held the "crud" in suspension long enough to get it out the engine, and therefore, I consider it "did its job." From there, who cares? My cars won't last any longer or die any sooner because I looked or didn't.

While I must admit your observations HAVE caused amusement, my point about making the judgment you did is this: visual observation is purely anecdotal. It fits right in with another popular "car talk" element, filtration. I'm sure you've seen one or more of the many "oil filter studies" that float about the Internet rather constantly, in which an untrained person with a cutoff wheel, a few extra dollars, a digital camera and some time to waste buys several brands of filters, cuts them up, measures the media and pronounces "this is a good one" or "this one is garbage." In light of these discoveries, I find it hard to believe the either the oil or filter manufacturers would bother spending so many zillions of dollars and man hours testing their products when determining "quality" is actually SO simple!

But maybe, just maybe, both the oil and filter mfrs are guided by the adage "There's more than meets the eye."

So again, if it makes you feel better, please have fun looking at your old oil! Or send it in for lab analysis, show us your numbers, and then we can talk!

Rick

How do you know it got ALL of the junk out, and not deposited most of it on your engine internals? Do numbers from oil analysis tell you that?

Well, good for you, I guess.

M.J.

Hi,

There is only ONE way to get ALL the crud out: tear down the engine and clean all the parts!

Short of that, there will ALWAYS be a certain amount of crud deposited somewhere in the engine. The places it's going to build up most, assuming regular oil changes, will usually be benign "nooks and crannies" where oil splashes and lands, then sits w/o being able to circulate quickly. With MOST engines, this is NOT a problem (however, there ARE some engine designs that are problematic, but they're problematic REGARDLESS of the oil being used. One case in point being the infamous Toyota "sludge engines." Not to single out Toyota--many other mfrs have had one or more of these "problem child" engines.) As a general rule, those places that have either pressurized oil flow, or a lot of oil flowing over them all the time, like return galleries, will show the least buildup of varnish or other crud. That's simple enough to see in a teardown.

What does oil analysis do for you in this regard? It simply tells you WHEN you need change your oil because it's reached the maximum level of contamination it can handle w/o causing "excessive" wear or damage to your engine. I say "excessive" because the engineers design a certain amount in when determining THEIR idea of the life expectancy of the engine. By changing oil and filters far more frequently than suggested by the owners manual, we MAY be able to cut the wear factor far below the design level. And then again, we may NOT. This is ONE of the reasons you will probably see far more of the "high mileage" engine reports (a quarter million miles or more is a number that sticks in my mind) are from guys who change at more frequent intervals. But the frequency of oil changes is only one of many factors in engine longevity, so it can't be pointed to as THE reason a particular engine lasted a certain number of miles.

So while the best way to achieve dependable oil analysis figures is probably to start with a "new" engine (crate new or rebuild new) and get a baseline figure, then have a series of oil analyses done at differing intervals to determine what the best "average" interval is, you can start at any point and at least have a baseline figure to use to estimate your engine's condition. At first, while the engine's wearing in, certain numbers will be high, then they'll usually stabilize, so you can tell how far from a given number you've "strayed" which CAN be a useful diagnostic tool if you're running a fleet. For the individual owner, it's probably more a "feel good" thing, since most of us aren't going to stop what we're doing and tear apart an engine when we see a "high" number for say, a bearing material, indicating bearing wear. We're going to watch the oil pressure gauge, and figure as long as it's ok, that bearing hasn't worn badly enough to worry about.

This is why I suggested you siphon the "clean" oil off your specimen and have it analyzed! Most of the contaminants that cause wear, the particulates, will have settled out and won't be present in that "clean" sample. Other items, such as metals, may or may not still be present. But the analysis figures will tell you "change" or "keep" even so.

Another thing oil analysis will do is tell you what you're LOOKING at is anything, or nothing, in the grand scheme of things. One of the things your oil does is "clean" in the sense it carries crud to the filter to be caught and held for disposal at the next change. One of the criteria the engineers look at is the "size" of the crud, measured in microns (1 micron = .000001 m = .000039 in), and there are ranges to be concerned with, ranges not to worry about. Most sources you can easily find suggest most of the engine wear is caused by particles in the 5-20 micron range. A majority of oil filters on the market do VERY well at removing crud above 20 microns, some do a pretty good job in the 10-20 micron range (brand and model CAN'T predict this! Only testing does--one catalog number may be excellent, another barely passable), few do so well below 10 microns or so. Why not? Engineers must balance flow and pressure against efficiency. They CAN filter out much tinier stuff, but then you'd be changing your filter every few hundred miles when it clogged, and who knows how long your engine would last w/ the reduced flow? So there's a balancing act involved.

Now to take this further, we have bypass filtration. A bypass filter CAN get out extremely tiny junk but it can't flow much. So I'm gonna illustrate why your "visual" estimation of how good a job your oil is doing can be flawed.

Years ago the Frantz people introduced bypass filtration to the masses with the "toilet paper" filter. The people selling these filters had a neat visual aid they used to show people how well their unit worked. They had a test bench set up with a container of clean oil, a pump, a full flow filter and a bypass filter. There was a switch to put the bypass filter in the loop or take it out.

They would start the machine, and you could watch the oil go thru the full flow filter and the bypass filter. Since it was clean oil, it wasn't an impressive sight at first. But then they would isolate the bypass filter, and introduce a bit of carbon black to the "clean" oil. Instantly it would turn jet black! And as it circulated thru the full flow filter, there was NO change in color. Then they'd turn on the bypass filter, and in a couple of minutes, the oil was back to being "clean" again.

So the first thing that would go thru one's mind as they watched this was "that oil is filthy" followed by "my oil filter's not doing much of a job" and, the salesman hoped, you finished with "I'll buy one!"

But as I mentioned before, there's more than meets the eye! Carbon black is LESS than 1 micron in size. So it's NOT a player in the wear equations! But it certainly makes the oil LOOK bad! And, using your visual "settling rate" estimation, it would stay "in suspension" for an extremely long time simply because the mass of the particles is so low it takes "forever" to settle out. Oil analysis would help you determine if you're looking at actual wear particles, or just "carbon black" type contaminants! One would dictate it's time to change your oil, the other is strictly "fuggedaboutit" territory.

So "you pays your money, you makes your choices, and you takes your chances!" IF you're blessed with the resources to take two IDENTICAL engines, and run them under IDENTICAL conditions side by side where the ONLY variable being changed is the oil being used, change intervals, filter, or some other item, you can come up with decent data on what's "best." Since the mfrs DO have these resources, and DON'T recommend any particular oils or filters as a result of their testing, there should be a lesson in there for us mere mortals who have to work hard just to have one or two vehicles to drive! Otherwise, we're just arguing how many angels can dance on the head of a pin... and that's why the man insisted on "Show me your numbers...!"

Rick

If a particular type oil is behaving substantially differently than other well known "good" oils after its has been drained out of the crankcase chances are it was also behaving differently when it was in the engine. Don't you agree?

The scientific process starts with observation, visual, and other. Findings collected this way are a basis for forming hypotheses. Hypotheses get proved or disproved by further testing.

So basically you are right, testing would be needed to establish for sure that the oil was no good. I should't have stateted that the oil IS bad, just that there are some preliminary indications that the oil MAY BE utter crap.

Personally, when I see something fishy, I decide to optimize, i.e. save on the cost of further testing and investigation, and I avoid the product altogether, aware that there is a probability that I may be wrong. You may call it I get spooked, or follow a "buyer beware" approach, or something. By the way I think I behave like the average consumer (?).

Just came from Walmart w few minutes ago, the oil brand is called Accel, and there are several viscosities- I used 10w-40.

M.J.

Hi,

Does this oil have an API rating on the bottle? If so, does it have the SAME API rating as, say Mobil 1, which I think most people would agree is a "premium" quality oil?

If they both carry the same API rating, we know they both have met a MINIMUM set of test requirements, and are therefore equal at worst. Now, Mobil 1 MAY be far superior to Accel, but we CANNOT prove that without scientifically valid testing protocols. Lacking those, any supposed differences are anecdotal or advertising hype. So, you may OBSERVE that your engine appears to be cleaner w/ Mobil 1 than with Accel (or any other.) You then form your hypothesis that M-1 is the better oil. Now the process DEMANDS proper testing to establish the validity of your hypothesis. On this we agree.

Where we disagree is that you've initially tried to establish your hypothesis (which MAY very well be valid, but we don't know!) as a basis to describe one product as "crap" (or otherwise inferior) without benefit of testing. My point has been, and remains, that the manufacturers HAVE done the testing, and haven't found enough significant difference to recommend one brand over another, AS LONG AS each brand carries the recommended rating. I'm sure they've observed the same things you have, but nobody's "shown us the numbers" to show that observation carries much weight, if any, within the parameters they feel are important.

A last note on "observations": the behavior of your oil outside of the engine cannot be correlated to its behavior inside on its face. We could come up with all kinds of scenarios, some of which would support your idea, some of which would not. One, for example, that would not might run like this:

We have two otherwise identical cars, and we fill one with 10W-40, the other with straight 40 wt. We also have two extra quarts of each the

So "You pays your money and you makes your choices" on whatever makes YOU happy, confident, whatever. You're free to think "my choice is best because...." That's one of the benefits of having a competitive market place to choose from, and that's about the last I care to say on this.

Rick