HDEO phosphorus levels (ZDDP levels)

[Jim Allen]

My understanding is the the reduction in ZDDP came as much from the motor industry as anything. The gubment supplied indirect pressure by requiring a higher performance standard over a longer period (8/80 warranty). I don't think it's so much an issue of outright failure as it is a degradation of performance as the honeycomb is slowly contaminated. The OE wanted the the lower ZDDP levels to make the longer interval a "fail safe" deal.

In reality, for newer engines, the current levels of ZDDP are more than enough. Nobody in mainstream manufacturing really cares that much about the older stuff, (obviously preferring that you bought their new stuff). It's clear that a good deal of the older stuff can get by with the low levels but it certainly reduces the margin for error (sometimes to a razor thin level) and it creates a bunch more caveats with regards to certain types of engine, break in of new engines, etc.

All the SM rated HDEOs I know of run in the 1,000-1200 ppm range and that's pretty much a SG-SL levels. If only they built a wider range of HDEO viscosities to choose from, though 10W30 covers most everything old.

 

[Ken2]

The P levels in SN are the same as SM. Ditto for GF-5 vs. GF-4. What did change in this regard is a reduction in allowable volatility to keep more P out of the catcon.

Yes, some ZDDP is necessary, or at least it seems that way, or maybe this is just an economic argument. The ILSAC group is comprised of auto people, oil people, and chemical people. The auto people want better oil to reduce their warranty costs, as well as being hammered by the EPA to keep emissions down. The oil people want cheaper oil to improve their sales. The chemical people want something that can be actually achieved. Lots of ZDDP meets three out of four of these requirements. Little ZDDP plus other stuff meets all four.

 

[Jim Allen]

Originally Posted By: Ken2
The P levels in SN are the same as SM. Ditto for GF-5 vs. GF-4. What did change in this regard is a reduction in allowable volatility to keep more P out of the catcon.

Yes, some ZDDP is necessary, or at least it seems that way, or maybe this is just an economic argument. The ILSAC group is comprised of auto people, oil people, and chemical people. The auto people want better oil to reduce their warranty costs, as well as being hammered by the EPA to keep emissions down. The oil people want cheaper oil to improve their sales. The chemical people want something that can be actually achieved. Lots of ZDDP meets three out of four of these requirements. Little ZDDP plus other stuff meets all four.


Well said!

 

[A_Harman]

Originally Posted By: d00df00d
Still waiting for evidence that "there is no good antiwear-additive substitute for ZDDP."


Perhaps you could post some links to reports showing that there are good antiwear substitutes to zddp. I am intrigued by the new titanium additive technology, but would like to be "calibrated" to understand how much Ti is required to replace zddp. zddp is hard to beat as a multipurpose additive, giving anti-wear, anti-oxidation, and corrosion protection.

 

[440Magnum]

Originally Posted By: Gokhan
With regard the catalytic converters, my 85 Corolla, which was built during the emergence of the strict emission regulations, has a three-way catalyst and an oxidation catalyst.


Which is absolutely stone-age compared to the catalysts of today. Also there was no requirement that your stone-age catalyst keep such a high percentage of its initial effectiveness for such a long time as modern catalysts are required to do.

 

[Gokhan]

Originally Posted By: 440Magnum
Originally Posted By: Gokhan
With regard the catalytic converters, my 85 Corolla, which was built during the emergence of the strict emission regulations, has a three-way catalyst and an oxidation catalyst.

Which is absolutely stone-age compared to the catalysts of today. Also there was no requirement that your stone-age catalyst keep such a high percentage of its initial effectiveness for such a long time as modern catalysts are required to do.

I doubt its construction and alloys are much different than that of the current cats.

 

[Trvlr500]

Originally Posted By: 440Magnum
Originally Posted By: Trvlr500

I fail to understand how ZDDP in the oil will hurt a catalytic converter unless the engine is using or burning oil to begin with. I doubt ZDDP really hurts catalytic converters at all. I'd like to know how many cases were "PROVEN" where ZDDP ruined a catalytic converter if the engine was in good running condition and wasn't using/burning oil.


There are a few flaws in your logic here. First off, EVERY piston engine burns oil all the time. Very small amounts, but you can't eliminate consumption, because if you did the top compression ring would wear out in just a few miles. So its a GIVEN that oil does get burned and the byproducts of burning do go through the catcon.

Second, there's no argument that ZDDP does inactivate catalyst materials, just like tetraethyl lead does. The chemistry is irrefutable.

Third, its a SLOW process and a cumulative process. Every thing that goes through a catalyst which can bind to and inactivate catalytic materials does so and will very slowly reduce the amount of active catalyst available to process normal exhaust gasses. Every catalyst molecule that gets "poisoned" is gone forever. Kinda like brain cells when you go out on a bender... eventually you start to sound like Ozzy Osbourne ;-)

Fourth, you're right that during the life of most well-maintained vehicles, you could use oils that have very high ZDDP levels and the catalyst activity would remain high enough to pass emissions tests. But the manufacturers are being held to much longer emission system warranties than they used to, and the desire is to have enough safety margin in the whole emission system design so that it can undergo a LOT of degradation due to poor maintenance or even outright abuse and continue to function well enough to pass emissions testing way out to 200k or more miles. In addition, modern catalysts are more sensitive to "poisoning" than ever. We're talking about cars that come off the assembly line SO clean these days that you literally could lock yourself in a closed garage with one, idling, and be unable to get a case of CO poisoning. CO2 suffocation, yes, but not CO poisoning. That's where the last little bit of margin gained by reducing ZDDP concentrations comes into play- it increases the design margin.

And finally- the modern engines that low-ZDDP oils are targeted toward just DO NOT really need a sacrificial EP additive the way old engines with high cam/follower contact pressures did.


I have heard that the warranty needed to be extended on the newer cars as far as emissions are concerned. I still see no reason why they have to regluate the oil with specifications that don't allow cheaper oil manufactured by larger companies such as Pennzoil in thinner weights with sufficient ZDDP in them for the older vehicles so many own.

I also realize that detergents and ZDDP "compete" for surface area inside the engine but they could solve that problem as well with fewer detergents for older engines.

Having to buy boutique oils or add the ZDDP yourself just doesn't make sense.

 

[Michael_P]

You would think a herder metal such as moly would wreak more havoc on a cat than the softer metal of zinc. I really don't know, just throwing that out there.

 

[A_Harman]

It's not the zinc that harms the cats, it's the phosphorous.

 

[dparm]

Some of those additives are in suspension or have supplemental additives to prevent that, Michael.

 

[A_Harman]

Originally Posted By: Trvlr500
I have heard that the warranty needed to be extended on the newer cars as far as emissions are concerned. I still see no reason why they have to regluate the oil with specifications that don't allow cheaper oil manufactured by larger companies such as Pennzoil in thinner weights with sufficient ZDDP in them for the older vehicles so many own.

I also realize that detergents and ZDDP "compete" for surface area inside the engine but they could solve that problem as well with fewer detergents for older engines.

Having to buy boutique oils or add the ZDDP yourself just doesn't make sense.


That's the shape of the world we live in. New oil specifications from the API are defined in cooperation with the auto manufacturers, and oils are formulated for new cars. Almost all new engines have roller-follower valvetains, so they don't require large amounts of zddp. If you have an old engine with slider cam followers, use a throwback oil such as Valvoline VR1 or Brad Penn, or a modern sythetic, and supplement it with ZDDPlus or Redline Break-in Oil Additive. I know it's a pain, but that's just the way things are.

 

[Gokhan]

I find the ZDDP in oil quite analogous to fluoride in toothpaste. You can't do away with it -- it will result in too much wear in your engine or tooth -- but you need to be conservative about it -- too much phosphorus will poison your catalytic converter as too much fluorine will poison your body.

The mechanisms of the two are different though -- ZDDP forms a thick protective layer woven by phosphorus atoms whereas fluorine helps rebuild the enamel.

 

[Michael_P]

Thanks dparm for the answer. Even after I mis spelled harder.