Can you explain where those additives go?
Engineering Explained discusses ZDDP
- Thread starter Shel_B
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No need. Troll confirmed.
I believe the answer to that is, yes.
He believes you are a troll.
He is not alone in that belief, because of your wild claims about Slick 50 and your wild misinformation about ZDDP, as evidenced in this thread.
Man...Slick 50...back in the mid-'90s when I was in grad school and worked at a bike shop as a wrench, we used to sell a Slick 50 service for suspension forks. We had 2 PVC sleeves that we filled with Slick 50 and let the stanchion tubes sit overnight in them. It was an add-on service. I guess now we just get the Kashima coating for forks/shocks/droppers. Today if I had a shop I'd sell Liquimoly Ceratec service and do the same 
OVERKILL
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No, as @RDY4WAR clearly detailed, they aren't. They do the opposite, diluting the additive package and decreasing the quality of the lubricant.
ZDDP is the primary anti-wear additive and the largest by volume. VII polymers are extremely heavy and while cheaper ones can shear, they do not evaporate. Lighter fractions of the base oils can be volatized, and oil mist can make its way into the PCV system and result in some burning off, but this is dependent on engine and PCV/breather design.
ZDDP as an active antiwear molecule gets broken apart to create the phosphate layer on metal. Then it gets worn off so that zinc and phosphorus are floating around as who knows what but its not ZDDP anymore so even though the elements haven’t gone anywhere and will still show up in a UOA the additive is getting used up over time.
So yeah if you knew the ZDDP was 80% broken down in your oil, adding a touch up could bring the levels back up to what they were when the oil was new but again how do you know how much ZDDP is left? You don’t with the type of UOA we all use.
Now some additives will disappear over time like boron when it’s used as a detergent and suspend globs of crud that eventually get trapped in the oil filter along with the boron. You’ll see the ppm drop off considerably over a run.
That would be a new one to me. After years of working in an industrial research laboratory, I’ve never seen the solute distill out of a solvent
Yes as you note, a spectrographic analysis is an insufficient analytical method determine compounds. And especially whether they are in an active configuration.
Probably NMR which is what I suspect you meant to say. There was a post a while back ago that referenced a study that showed NMR could distinguish between active and inactivated ZDDP and gauge the effectiveness. You’re not going to image anything, but you are looking for deshielding of a central atom.
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You're better off and cheaper to just top off with a 0.5 qt of engine oil. I addressed the other additives in my reply. You're making a compelling case for being a troll so I'll let you beat your chest alone under the stone bridge and move on.
Potato potato. You’re throwing something in a reasonably strong magnetic field and tickling it with radio waves, it’s the same physics.
https://www.machinerylubrication.com/Read/764/nuclear-magnetic-resonance-additive
This page has a pair of graphs at the end and if you look past the poor data presentation, seriously how do you not make the two x-axis ranges identical or have any scale on the y-axis, you can see the additive fingerprint disappear in the used oil.
Well sort of, you’re not obtaining an image and when I researched the hydrolysis of polyimide I didn’t use an MRI machine at the hospital.
But yes that’s the article I recalled. I’m still not convinced that properly executed FTIR wouldn’t show the same thing but it’s an interesting article.
There are some papers out there on the use of Raman spectography to monitor ZDDP films.
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The additives vaporize and the level goes down is the rationale here?
4WD
$50 site donor 2025
Gotta be a hawk-eye or you’re gonna miss it
No that is most certainly not the rationale.
Pretty good video. So high ZDDP increases engine friction, poisons cats, and is not needed on roller cam engine.
On non roller engines, where you don't care too much about the cat, or engine friction, higher ZDDP will help wear.
As generally known. One of the reasons say on Mobil 1 5w50 Supercar which was designed for a non-roller engine, they ramped up the ZDDP and reduced the detergents to help wear.
On non roller engines, where you don't care too much about the cat, or engine friction, higher ZDDP will help wear.
As generally known. One of the reasons say on Mobil 1 5w50 Supercar which was designed for a non-roller engine, they ramped up the ZDDP and reduced the detergents to help wear.
edyvw
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There is a limit on ZDDP to be compatible with CAT's. What is high ZDDP? Euro oils have higher ZDDP (hence API SL designation still for many XW30 oils with Euro approvals).
OVERKILL
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Higher ZDDP can lead to catalyst poisoning if a lot of it ends up in the exhaust system. While less is required with roller followers and roller lifters, this does not mean that other areas may not benefit from slightly higher concentrations.
Depends on the non-roller application here. An old broomstick cam'd SBF or SBC doesn't require a whole heck of a lot of ZDDP to keep the parts separated. A cam-over-bucket application doesn't either, generally, unless it's design is such that it produces high pressure on a small contact patch (VW PD engines for example).
Mobil 1 15W-50 was broadly spec'd for GM roller applications in Corvette and Camaro.
Ultimately, my view on it is that phosphorous levels, unconstrained, generally land at around 900-1,000ppm for ideal protection in most passenger car applications, as evidenced by the full-SAPS Euro oils. Even the C3 oils typically have phosphorous approaching the 900ppm limit.
Where we see considerably lower levels of phosphorous is in the API/ILSAC oils, which can be blended very inexpensively, and typically have a higher volatility ceiling. These are also lighter. You combine those things, and odds are much higher that the oil is going to end up in the exhaust system, so catalyst protection becomes a bigger focal point, so we see phosphorous not only more restricted by regulation, but we see less of it used.
Phosphorus can disappear from the oil over time due to its volatility. The API standards even require oils to be tested for this, requiring a minimum phosphorus retention of 81% in the Sequence IIIHB engine test. The concern with this is keeping the phosphorus out of the catalytic converter.
The breakdown/depletion of ZDDP is a separate issue. When the ZDDP is sufficiently depleted, friction and wear will increase. This can happen even if there's no noticeable loss of phosphorus, and so it won't be obvious on a UOA. The same thing happens to friction modifier and other additives. Studies on additive depletion use different types of spectroscopy to measure additive depletion.
SAE 952543 is a good study on this. In this case, ZDDP depletion occurred within 6,700 km of commuting, and the MoDTC was 70% depleted. The oil's friction performance essentially dropped to that of the base oil. They didn't measure engine wear, but I expect it would have increased as well.
That study is from 1995. Modern oils should perform better since the API standards have more stringent aged-oil fuel economy tests. Though, the modern tests still allow fuel economy to drop by several percent over a typical OCI due to additive depletion.
Here's an example of additive depletion from another study:
The breakdown/depletion of ZDDP is a separate issue. When the ZDDP is sufficiently depleted, friction and wear will increase. This can happen even if there's no noticeable loss of phosphorus, and so it won't be obvious on a UOA. The same thing happens to friction modifier and other additives. Studies on additive depletion use different types of spectroscopy to measure additive depletion.
SAE 952543 is a good study on this. In this case, ZDDP depletion occurred within 6,700 km of commuting, and the MoDTC was 70% depleted. The oil's friction performance essentially dropped to that of the base oil. They didn't measure engine wear, but I expect it would have increased as well.
That study is from 1995. Modern oils should perform better since the API standards have more stringent aged-oil fuel economy tests. Though, the modern tests still allow fuel economy to drop by several percent over a typical OCI due to additive depletion.
Here's an example of additive depletion from another study:
