Tegger's real-world oil consumption

jim wrote in news:BoCdnR030_d3kpDRnZ2dnUVZ snipped-for-privacy@bright.net:

Definitely. 2,500-mile-old oil is darker and easier to see on the stick. I do find it a bit difficult to locate the top of the "meniscus" with brand- new oil, since it's so clear. It is possible that my second check is more accurate than my first, for this reason.

A fresh batch of Mobil 1 went in this evening. I took the opportunity to try and determine exactly where the "live" area of the dipstick was in relation to the oil pan.

The bottom of the dipstick is, as far as I can measure, about an inch below the bottom surface of the oil pan mounting flange. A bit below that point is when the pan's "shallow" area suddenly takes a dip into the "deep" area.

The "shallow" area slopes downwards maybe 1/4" from the flywheel end to the "deep" end, maybe a 6" distance. It then takes about a 12mm radius and then heads straight down to the drain bolt.

Based on these observations, I believe the oil level does drop fairly linearly, since there is no drastic change in oil pan shape from upper mark on the stick to lower mark on the stick.

"C. E. White" wrote in news:huj4a6$tvt$1 @news.eternal-september.org:

"Light components" of the oil do NOT "boil away". That is, flat-out, a myth. I have this on /very/ good authority.

As for oil burn-off, well yes, that is precisely what I am trying to measure.

Water is not an issue here, trust me. Fuel, however, is. The one analysis I had done in 2005 indicated that I had about 2% dilution after 3,000 miles.

Soot and dust make up the smallest part of the oil, by far. There isn't nearly enough there to affect the level.

sorry dude, your "authority" has that very wrong - they clearly have never done fractional distillation.

that contradicts statement above...

that's not good, especially not for a vehicle making longer runs like yours. did you rectify the problem?

///snipped///

Being that you wish to nitpick the method used in the subject test, I would point out that what was described was a "method" NOT a "methodology"!!!!A common mistake used even by those somewhat familiar with scientific testing.

DaveD

If you simply figure out how much the engine used over the entire

Yes what the OZP was described was a method. But you apparently completely missed the point I was attempting to make. He is using the wrong methodology. Yes I did make the mistake of critiquing some of the methods also when I should have stayed with the main point which is that the OP is using wrong methodology. Attempting to make more than one point per posting tends to confuse the dim twitted.

The idea of using statistical analysis to solve what is really an accounting problem is the wrong methodology. Let me give an analogy. lets suppose you go to the grocery store and you put 42 items in your shopping cart. When you get to the checkout counter you tell the clerk that you are going to pick 17 items from the cart and through scientific statistical analysis of the 17 picked items you are going to determine how much you will pay the store. The clerk will inform you that is the wrong methodology (more likely the store will just call the cops). It doesn't matter if you argue that you are going to use well established statistical methods and that you are extremely knowledgeable in regards to scientific testing - the store will still insist that is a ridiculous way to approach the problem. The application of statistical analysis to solve what is a basic accounting problem is using the wrong methodology. In the OP's case the specific methods used also happen to be suspect, but even if the statistical methods weren't flawed the fact remains - he's not using the best methodology.

Once one has abandoned what is a ridiculously unreliable methodology for this problem then you can start to think about the specific methods one might choose to use. For instance, since the OP appears to be numerically challenged he could account for the oil consumed in the following way: He could keep all the containers that the oil comes in. Then at 3000 miles when he drains the oil he could carefully and thoroughly extract the oil from the oil pan and oil filter and put the used oil back in the original containers to the original level. After

42000 miles simply divide 42000 by the number of empty containers to determine that miles per quart number that he is looking for. No record keeping or paper work will be necessary. And my strong suspicion is he would arrive at a substantially different number than he is now.

-jim

This Excel data does not even look like the same data as the PDF. For example, in your PDF file you have what is labeled a first reading at

321,771 miles and a second reading at 323,206 miles. That is an interval of 1435 miles. I don't see any interval in the Excel file that is even close to 1435. I see another 1st reading at 310,440 and a second reading at 311,635 which is an interval of 1195. But I see nothing in the excel file that corresponds with that number either. I'm sorry I don't know what to make of your data. I don't know if you have a lot of typos or arithmetic errors or if something else is going on.

I already told you the data is too spotty to actually know what the oil consumption might be to any reasonable degree of accuracy. You should be able to determine the consumption in 3000 to 6000 miles with much more confidence in the accuracy than you can get from working with this data. Whatever you are doing and whatever your engine is doing appears to be fairly consistent. That much can be inferred from looking at the data. But it looks to me that it is quite likely that your results could be consistently wrong.

You can't do it my way with that data. That's my point - GIGO (look it up if you don't know)

-jim

so where is YOUR analysis, asshole? what - you don't have any? and you can't do the stats? and you don't actually have a damned thing to say other than whining loser bullshit? what a total non-surprise.

This would be a bad application for stats. I think the OP's study does an excellent job of illustrating why statistical analysis can be an exceptionally poor way to get a good answer. But what can you do - some people are so misguided they will attempt to use statistical analysis to tell them what day it is.

-jim

yeah. said by the contribution-free asshole that doesn't have the balls to actually walk his talk.

Are you trying to champion stupidity?

I have been saying it is really dumb to use statistical analysis for determining something that is a basic accounting problem like determining oil consumption. And the only response you come up with is "why don't you show us the statistical analysis of oil consumption you have done". Are you saying If I can't match your stupidity - I shouldn't post?

jim beam wrote:

I apparently don't have what it takes to be as dumb as you that is for sure.

So let's see if i can follow this down the rabbit hole.... that would make you the one that can't read??? or..... are you the other one who sure is dumb???

wow, you just removed the question as to whether you're illiterate or deceitful - and you did it on your own!!! i wonder if you're dumb enough to not learn from that mistake??? [rhetorical]

Take a deep breath and exhale slowly before you melt into a blob of gurgling green goo.

jim wrote in news:daOdnX-SJMgy0ZPRnZ2dnUVZ snipped-for-privacy@bright.net:

You said this: "The correct method is easy. If you summed how much make up oil you added in total plus how much less than full it was at the time of oil change, you would get a number that represents the total consumption over the entire 42000 miles. You then make the calculation on that total consumption and total miles."

Firstly, I never said I was doing a test over the whole 42,000 miles. I said I was doing ~1,000 mile tests twice within every batch of oil, which was roughly every 3,000 miles.

Secondly, doing it /your/ way results in a number that's about 1/2 of one-percent different from the number you'd get when doing it /my/ way.

My raw numbers say:

17,892 miles within the test periods. 10.817 quarts consumed (AKA "required to top-up to original level").

So doing it your way (as you describe above):

17892 / 10.817 = 1654 miles.

Doing it my way (averaging the extrapolated mi/qt):

21425 / 17 = 1663 miles.

Comparing the two:

1654 / 1663 = 0.9945, or 0.55% difference.

jim beam wrote in news:14GdnY9PBtZLOJDRnZ2dnUVZ snipped-for-privacy@speakeasy.net:

My sources do fractional distillation for a living.

The "boil-off" thing is, flat-out, totally, completely, utterly, absolutely, wholly wrong in every possible and imaginable way.

"Burn-off" means consumption via worn rings and seals, not evaporation due to some sort of "boil-off".

I don't know; I never did another analysis.

Considering that there apppears to have been very little change in oil consumption since 2005, and considering the oil-light still goes off about as quickly as the one in our 130K mile Toyota Tercel, I think the amount of fuel in the oil is not creating a panic situation.

no it's not - it's the fundamental principle of distillation. motor oil is a mix. that means means there are different components. different components have different boiling points. and that's /before/ there's any breakdown, which by definition means different boiling points all over again.

either we need to re-write the chemistry books, or you're somehow asking your sources a question that's got them talking about a different point than than the one we're discussing.

it doesn't burn until it vaporizes. it doesn't vaporize until it gets heated. and when it get s heated, some fractions vaporize [evaporate] before others. see above.

are you not interested in the fact that you're apparently wasting gas?

further reading:

jim beam wrote in news:kuKdnSKA1f2xe5PRnZ2dnUVZ snipped-for-privacy@speakeasy.net:

Have you considered that the evaporable fractions may have been removed when the oil was made?

Have you considered that oil is /not supposed/ to evaporate, and may have been /designed/ not to evaporate?

I think the wastage is very, very tiny.

My crankcase contains, nominally, 135 ounces. 2% fuel inside that 135 ounces works out to about three ounces. And that's after 3,000 miles.

Any fuel not absorbed by the oil is finding its way back into the intake via the PCV system. Which, of course, is exactly why the PCV system was devised in the first place...

I can also tell you that any fuel in my oil is undetectable by my nose, even when I compare/sniff brand-new oil and the stuff I just drained. I once had a fuel-pump diaphragm break with my '75 Corolla. Oh BOY did that oil ever smell of gasoline!!

BTW, my oil analysis was done in 2006, not 2005. I misread the report before. I might get another one done, just to see if high-fuel still presents itself.

yes indeed. but that link i carefully gave you, and which you have equally carefully snipped, discusses evaporation with respect to solutions. you should read it.

as for the question you've asked your sources, i suspect it was along the lines of whether oil boils at operational temperatures and the answer of course is "no". but if you read and think about the link i gave you, and employ some common sense [how does motor oil have a smell if it's not losing vapor from its surface?], then you'll see some logic in what i'm trying to communicate.

well, according to the argument you've been using above, that would be impossible. this is why it's important to understand the principles.

that would be good.

the reason i raise it is because that's a high percentage for a vehicle that runs for extended periods at full working temperature and thus should be seeing it all evaporate. to be retaining that percentage, it has to be being "replenished" at quite a rate, and that is costing you money. if it was just a townie runabout, colder average operating temps and shorter durations would mean lower evaporation and that percentage might be less of an issue.