Oil analysis with engines that consume oil

[Kernel Potter]

Hello everyone. I was thinking about oil analysis and the effect of the results when an engine needs a fair amount of oil additions between changes and opposed to an engine that doesn't consume much oil at all.

Say someone uses brand X oil and puts 6,000 miles on it but has to add a quart of oil, say every 800 miles as opposed to another person using the same Brand X oil but would barely have to add any oil in the same amount of miles.

See what I'm getting at here? The engine that needs frequent oil additions has the potential to make the oil analysis look as though marginal or bad oils are the best thing since sliced bread. It also seems a way to introduce variables that can be undocumented to make oils test better than they really are; say for marketing reasons etc.

Does anyone have any insight or ideas about this?

 

[Al]

This is not a flame: But with consumption of the degree you are dealing with. Why bother. The goal of oil analysis is to be able to prolong engine life. I would stick that oil analysis money into the kitty to buy a new engine.

 

[Kernel Potter]

Al,

My post was simply questioning any potential variables that may falsely rate a given oil brand much better in an oil analysis than they would typically be capable of getting.

Isn’t oil analysis also used to see how well an oil holds up to oxidation, acid build up, wear protection etc? As an example; to see if say, a $7 quart of Red Line oil is really the superior oil it’s supposed to be compared to a $1 quart of Walmart mineral oil?

This isn’t a flame either, but did you actually read my entire post and understand what I was asking?

 

[Patman]

I totally understand what you are saying, because I was thinking the same thing! A lot of the guys on the LS1 message boards have oil burning problems for instance. Due to a poor PCV design that sucks oil into the intake, and poor rings, some of these poor souls are burning oil at the rate of one quart per 1000 miles, sometimes more! (two of my good friends that are due for engine rebuilds on their LS1s both burn a quart every 2-300 miles right now!)

Anyways, back to the guys with one quart per 1000 miles. If they run their oils for a 6000 mile interval, they will have added 5-6 quarts, essentially having refreshed the crankcase to the tune of an extra oil change's worth of oil. So in reality it's not going to show the truth about how that particular oil would hold up in the long run, since it's constantly being freshened up with new additives.

My car leaks out about 1/3 of a quart every 2000 miles based on what I can tell, so it's not that bad, but even still, I don't plan on adding any oil in the last portion of the interval, just so it doesn't skew the oil analysis results. I suggest the same for other people. If you know you're about to do an oil analysis in the coming weeks, don't add any fresh oil for at least the last 1000 miles if you can avoid it. The worst thing you could do is check your oil the day before you are about to drain it for analysis and add an extra 1/2 quart to a quart. Then there is no way you can be guaranteed an accurate test result. It would be like taking your sample with 3/4 of the used oil and then filling up the rest of the sample bottle with new oil.

 

[VaderSS]

First of all, if you have oil consumption problems, I don't see the point of running synthetic. I don't know the standard way of doing analysis, but for me, I started at 6000 miles, which I felt was quite reasonable for a synthetic. I then ran it again at 9000, then again at 12000. Once I had my baseline, which was the 11000 mile interval, I would run it at 7000 and again after I drained it. If you are considering running analysis every 800 mile (and don't own an excepionally rare, or expensive engine) I'd say just stick with 4000 mile oil changes and pocket $25 every 800. You'll have the money for a new engine long before it wears out.

 

[Al]

Yes, I did misread

anyway good question. I would think you could think of it as a straight dilution problem. In the simple case: If your engine consumed one quart and had 4 quarts origionally and you add 1, it would be close to saying that any metal ppm's would need to be multiplies by say 1.25 to account for the dilution. Now that won't be exact because it depends when you added the new oil. I think if you kept track of the amount used you could make an approximate adjustment. Viscosity and TBM I guess would be more complicated. I'm clueless here.

 

[MolaKule]

As I understnad your question and comments, I would say it would be highly unethical and suicidal to attempt to do such a thing to make oil analsis (say, a new formulation) look good.

Most test I have seen start out with new to fairly new engines (documented with engine type, initial mileage, driving conditions, etc) in order to get a good baseline, or starting point.

Let's take this scenario:
A trucking fleet with diesel engines. Synthetic oil company wants to see if synthetic oils show improvements over dinos.

Yu would normally run for the first 30,000 miles or so on the manufacturers suggested viscosity of dino oil to determine if any bugs (called "infant mortality") exist.

Then you switch over say 5 trucks to synth and maybe 5 others stay dino and start documenting the oil analysis from the 30,000 mile
oil drain. YOu document filter type, oil analysis, mpg, temps, etc.

For gas engines, you might simply install the
synth after say, 5,000 miles on dino (for the same reasons above)and then start your baseline.

 

[msparks]

quote:

---

Originally posted by Kernel Potter:
Al,

My post was simply questioning any potential variables that may falsely rate a given oil brand much better in an oil analysis than they would typically be capable of getting.

---

Usually the amount of makeup oil is taken into consideration. For one if you went 10K and didn't add any vs going 10K and adding 10 quarts sure enough the analysis would be totally different. Diluted wear numbers and stronger than normal additive numbers as well as TBN.

As it was said before, if you are usuing that much oil I would be saving for a rebuild or new engine.

 

[BOBISTHEOILGUY]

anytime oil analysis is done, there is a spot to mention the amount of make up oil used during this run on the oil.. ie... 10,000 miles on oil, 1 gal make up oil during this 10,000 miles. This is an indicator of how the is holding up with the use of make up oil. Yes, it does make a shoddy oil look better than it really is, especially if make up oil is put in shortly before the sample. This also can be seen in the analysis as it will show near the base lines additive levels and the wear numbers can still show high or what ever they were prior to the make up oil added.

So, makeup oil or not, this can be detected. When I look at the schaeffers oil analysis, just by looking at a couple of the additive levels compared to the milage I can tell if there was makeup oil involved.

 

[Kernel Potter]

Hey everyone, thanks for your responses. Especially yours Bob, it answered what I was wondering and how adding top off oil can typically be determined in oil analysis. You too Patman, as we seem to be on the same page with this.

The reason why I asked is cause I can see the scenario where someone uses a 59 cent/quart oil they find on sale and tell everyone it's every bit as good and better than mobil1/Amsoil/Redline etc. And when they go to test it after 7,000 miles, it looks like gold.... all the while they added about 5 oil changes worth of top offs during the 7000 miles.

Or another scenario is some desperate marketing scheme that does a long interval oil test on low cost oil comparing it to good group IV and V synthetics, yet never mentions that they top off the test engine with a few cases of oil during the testing etc.

By the way I don't have any engines that use oil and that was never the reason of my discussion. I do have an '87 Grand National w/ 73K on the odo that I'm about 350 miles into an Auto-RX treatment. I did want to clean that engine up for a few hundred miles before I found out about auto-rx. So about May 1st I put Delo 400 15w-40(my regular oil is Mobil1 10w-30) in it and had about 300 miles on the Delo before I added the auto-RX. It was excellent timing on finding out about auto-rx since I already had a mineral oil in there, which except for this specific circumstance, I never do. Does anyone know if Delo 400 15w-40 is a good oil to use with auto-rx?

I also have a new PT Woody that I changed the factory fill at 800 miles. I'm at 2,200 miles currently and the oil level hasn't budged.

If I get some results from the Auto-RX I'll post in that section. As a last note, I have the first filter I used with only the delo 400 for 300 miles on it and of course I'll have the filter with the delo and auto-rx treatment off in a few weeks. By any chance is there someone in the chicago area that has the ability to cut these open? I ask cause it will be a pain for me to find and buy the correct cuting equipment and I really don't plan on doing this during regualr oil changes. If anyone does it would be great and I could take digital pics of both elements and link them here.

Thanks again for the responses.

 

[BOBISTHEOILGUY]

Kernal,

This is a valid point and it is possible for someone to add makeup and make it look better than what it was. This cannot be controlled but with the quality of people who are out here sharing info, most I think will be truthful.

There is a few analalists that do this enough that would reconize (as I can with schaeffers oils) when the base oil additives are higher than normal for a certain amount of miles.

Another thing is to keep in mind that as time goes on, we will be able to see a "trend" in each type of oil, which if someone was to do that, would make it stand out above the others since not everyone would be deceptive.

This is one of the things I look for when looking at these oil analysis, is how well the oil holds up over a range of different situations.

 

[Patman]

The one great thing about the oil testing I will be doing with my wife's 2000 Honda Civic is the fact that in a 5000 mile interval I probably don't even add anything more than 1/8th of a quart of makeup oil to it, and this time around I probably won't even bother doing that much, so this way I can really see how the old formula Mobil 1 compares to the new Formula Mobil 1. Her car has had nothing but Mobil 1 TriSynthetic 5w30 since the second oil change, and when she has travelled 5000 miles (probably by around October I estimate) I will take that oil out and have it analyzed by Terry, then put in the new SuperSyn Mobil 1 (it should be in Canada by then, and if it's not, I will drive 90min to Niagara Falls NY to pick some up)

So that will be a true test of whether or not this oil is any good or not, and how it compares to the old formula. After that I will decide whether or not to stick to M1 in her car or switch.

 

[widman]

The effect you mention is definitely there, and as Bob says, when analizing we try to take that into consideration. On big engines I normally sample every 500 hours after the first 1000 up to 3000 or so. You can never draw a straight line through any of the measurements due to the oil added.
I tested Chevron against another brand identical engines for a potential customer, and at 1000 hours the other brand was "only" 50% more decomposed compared to the Chevron. But it has consumed 235 liters where the Chevron had only added 65 liters. So the difference was much more significant than it appeared.
You have to know how much was added, as well as a lot of other factors to get a valid trend.