Longhorncutlass

Allan R, you mentioned in another of my threads that my '87 Cutlass was lucky to be able to accept lower levels of ZDDP in its oil. What is ZDDP and is it a good thing or a bad thing for car engines?

I take it the tree hugging environmentalists thought it was harmful to nature so manufacturers are putting less of this compound into newer oils?

Run to Rund

Zinc diethyldithiophosphate is an anti-wear, anti-scuff additive that is very valuable in oil, especially with flat tappets (mechanical or hydraulic). Many use diesel oils so long as they are also rated on the S (spark ignition) scale because the C (compression ignition) rated oils usually have much more ZDDP.

MDchanic

Yes, for cars with flat-tappet camshafts.



You take it wrong.

The tree-hugging environmentalists were made sad by the malodorous pall that fell over many US cities at least occasionally (and LA almost all the time), that caused people to cough and wheeze (cf: Chinese cities today, with people wearing respirators as part of their normal daily dress).

The tree-hugging environmentalists prevailed upon the liberal warmonger Johnson Administration, which was in the process of murdering and maiming tens of thousands of Americans and Vietnamese, and which had just passed legislation that would allow black people to vote, and to use white-people water fountains, and had just created socialized medicine (called "Medicare"), to pass legislation that would require that automotive exhaust emissions be reduced.

As the car companies did research to figure out how to accomplish these reductions, they developed the catalytic converter, which removes many harmful things from exhaust gasses, and which is still used to this day.
Unfortunately, as it turns out, the catalytic converter is sensitive to impurities, and can be permanently "poisoned" by even small quantities of certain metals, rendering it useless. Initially, it was clear that lead could do this, and this was one reason why lead was removed from gasoline (the other was an epidemic of lead poisoning in children at that time, which was probably not from lead in car emissions, but that was not completely clear at the time). As time went on, it was discovered that zinc was bad for catalytic converters, too, so the amount of zinc in motor oils has been reduced. This is not harmful to newer cars, because they have roller-tappet cams, but the zinc is an essential lubrication component for flat-tappet motors.

If you google "ZDDP" you will find enough to read on this subject to keep you busy for the next several years.

- Eric

Allan R

Just found this thread but x2 on what Eric said. This topic of ZDDP has been beat to death on this site - all with the same basic conclusions. Bottom line is for your 87 Olds, use whatever brand of new oil you want in the manufacturers specified SAE range - it won't hurt your engine.

redoldsman

Sure seems like a long political answer to a simple question. I specifically remember the "White" and "Colored" water fountains being removed from the Montgomery Ward store in Monroe, LA in the late 50's during the Eisenhower administration. Now let me be clear, I agree with everything else you said.

MDchanic

Of course it was a long political answer, Red.
My answer was completely made up of mindless political characterizations (some of which were incompatible with one another), in response to the OP's reference to "tree hugging environmentalists."
Saying that a stereotypical group of people is responsible for a significant change to the chemical composition to a lubricant, with no recourse to historical or technical information, or to further thought, is farcical, so I provided a farcical response.

The point is that you cannot explain a technical engineering change with reference to the political stereotype of your choice. There may be people around who resemble political stereotypes, and those people may have some influence on some policies sometimes, but overall, there are reasons why things happen, and understanding those reasons helps us understand the world around us, including understanding how to best maintain our cars.

- Eric

1969w3155

Weren't the '87 307's using roller rockers, hence no need for ZDDP?

2Olds4U

Longhorn, This article may give you a little help understanding the need for it in older engines:
http://www.enginebuildermag.com/2013...80803-83615821

HTH

Longhorncutlass

Allan and 2Olds4U, I appreciate the good information.

wmachine

Decent article, but I totally disagree with him about not using a ZDP additive. If you read it carefully, he does not base his "no additive" stance on anything more than personal conjecture. His notion of not mixing has no basis in fact, when Lubrizol Corp has repeatedly shown that additives *do* get adequately mixed.

olds 307 and 403

An 87 307 does have roller lifters, any oil is fine. I can still find some older diesel oils and can get expensive ZDDP additives here. My cheap convient source for high ZDDP oil is gone. But according to some tests, ZDDP is only somewhat important in wear resistance. The whole additive package and how the oil is made is more important. Any original, non performance Olds V8 with factory tiny cam and worn out springs won't need it anyways.

2Olds4U

That is a possibility, Kurt. It is his perspective. My reason for posting was to give Longhorn some information pertaining to his vehicle and not necessarily gospel for today's vehicles.