Confused about ZDDP that was removed from oil...

[j_mac]

Can someone provide the timeline of what has happened with the reduction of ZDDP in modern automotive oils? When did they start restricting it? What API rating i.e. "SG SJ SL SM SN" did they first start reducing it? How much ZDDP is in the common motor oil you might see on the shelf at Walmart or the parts store these days. What year did the changes take place?
It just seems to me that say, back in 1995 you could walk into a parts store and grab a common bottle of 10W-30 and it would be suitable to use in an antique Model T, a vintage 1969 Camaro, your Briggs lawnmower engine, or put in the Mustang 5.0 you might have been using as a daily driver.
Nowadays there's ALL SORTS of specific oils for new cars, old cars, lawnmowers and what not and if you don't use the exact one for your application, then something is likely to be damaged. Can someone help explain?

 

[skyactiv]

If I remember, the big 3 wanted it lowered and the Japanese auto makers didn't want the levels changed. The big 3 wanted to preserve the catalytic convertor past the emissions warranty which was usually longer than the power train and bumper to bumper warranty. The Japanese auto makers worried reduced levels wouldn't be good for engines equipped with timing chains.

 

[CharBaby]

A little bit more ZDDP was removed between SG to SL and again from SL to SM. SM to SN has remained the same.

 

[Clevy]

Low tension rings. SM was the first spec to see lowered levels.
Low tension piston rings don't seal as well if not broken in properly,which leads to burning oil. Zddp fouls cats,so zddp was lowered to extend cat life instead of engine life however oil companies are using other compound instead of zddp.
The lowered level of zddp doesn't seem to be causing engines longevity issues as engines are lasting longer than they ever have,so whatever's in the oil is working.
That's my guess anyways. Someone here knows the actual truth though,I'm just guessing.

 

[regal55]

Originally Posted By: Char Baby
A little bit more ZDDP was removed between SG to SL and again from SL to SM. SM to SN has remained the same.


timeline ?

 

[carwreck]

Blackstone ran VOA tests on several old 1970's-1980's oils, in their "EBay" series. Lots of good info, but you will have to try to do some cross-reference through EBay searches if you want that exact time-line for these oils, because some old oil labels did not have the API grade.

Some older oils, like Wolf's Head SD 10W-40 had almost the same levels of Zinc/Phosphorus as modern API SN oils, but much lower detergent additives than modern oils.

Other oils, like Mobil Special 10W-30 and Texaco Havoline Super Premium 10w-40 API SF had Zinc/Phosphorus levels like the current Delo HD oil.

Blackstone old oil part 1
Blackstone part 2
Blackstone part 3

See pqiamerica.com for current oils and generic API grade timeline.

 

[carwreck]

Originally Posted By: j_mac

...Nowadays there's ALL SORTS of specific oils for new cars, old cars, lawnmowers and what not...


Some differences in oils are due to a specific test required by a manufacturer. This document from infineum is an example of testing different wear spec tests in the development of IIG, GF-4, 2001-2003.
http://www.infineum.com/sitecollectiondocuments/notebooks/gf4/section/performance.pdf

 

[Errtt]

Seems they gone to spiffing up other parts of additives so they could lower ZDDP and still maintain protection. Seems the Cats came in to hit ZDDP numbers.
Also changes of say moly, now some with the trinuclear moly which I guess is different. Numbers look lower than non-trinuclear type, but provides adequate protection.
Some have titanium while many other do not.
Just can't understand all of it so I be sure to use the recommended grade, and API spec.

 

[JAG]

^+1. The formulations did not simply get lower ZDDP and reduced wear protection. Other additives were changed to compensate as required to meet the ever-increasingly stringent oil specs that came out. If you still don't trust this you can use an oil such as Rotella T5 10W-30 which meets API CJ-4 and many diesel manufacturer specs.

 

[bluesubie]

For clarity, it the phosphorus in ZDDP that is known for clogging cats when burning a lot of oil.

http://www.gf-5.com/the_story/performance/

There are actually some mid SAPS oils out there (like Motul X-clean 5w30) that have high-ish zinc but are still low in phosphorus in order to meet ACEA C3 specs and EURO IV and V emission regulations.

-Dennis

 

[Garak]

And we also must not forget that just because limits changed, the oils' levels themselves didn't necessarily change. We have plenty of oils bumping at the upper phosphorous limits right now. Plenty of oils back in the day didn't have ridiculously high levels, though, and many were at the levels we see these days.

 

[wally6934]

Originally Posted By: j_mac
Can someone provide the timeline of what has happened with the reduction of ZDDP in modern automotive oils? When did they start restricting it? What API rating i.e. "SG SJ SL SM SN" did they first start reducing it? How much ZDDP is in the common motor oil you might see on the shelf at Walmart or the parts store these days. What year did the changes take place?
It just seems to me that say, back in 1995 you could walk into a parts store and grab a common bottle of 10W-30 and it would be suitable to use in an antique Model T, a vintage 1969 Camaro, your Briggs lawnmower engine, or put in the Mustang 5.0 you might have been using as a daily driver.
Nowadays there's ALL SORTS of specific oils for new cars, old cars, lawnmowers and what not and if you don't use the exact one for your application, then something is likely to be damaged. Can someone help explain?


This is the best information on ZDDP i have been able to put together, mostly from posts on BITOG.

http://www.pqiamerica.com/apiserviceclass.htm

API service classification chart from SA to SN with dates.


When ZDDP was not limited a good dose was around 1200 ppm phosphorous 1000 ppm zinc

There does not appear to be a published spec for zinc but it is usually about 100 to 200 ppm
lower than the phosphorous level.

SL is limited to 1000 ppm max phosphorous.
SM is limited to 600 ppm min/800 ppm max phosphorous.

The SN spec requires lower ZDDP levels for 20-30-grades. 40-grades are allowed to have
more ZDDP than the lighter stuff.

 

[doitmyself]

Originally Posted By: j_mac

It just seems to me that say, back in 1995 you could walk into a parts store and grab a common bottle of 10W-30 and it would be suitable to use in an antique Model T, a vintage 1969 Camaro, your Briggs lawnmower engine, or put in the Mustang 5.0 you might have been using as a daily driver.


Interesting that you chose 1995. Here's a fact that is often not remembered. Up until 1994-1995, nearly all of the common grade, over the counter engine oils were dual rated gasoline/diesel.

At that time, federal regulations removed the diesel rating of common automotive oils. I remember it well because I went to buy a case of 10W30 for my Kubota compact and the new labeling said "For gasoline engines only". I remember moving up to 15W40 because thinner grades in diesel were nearly non existent.

I called some oil company and asked if the labeling was just cosmetic, and they said "no", the new automotive oils contain less additives to meet environmental regulations (that's what I remember, vaguely).

So, yes, 1994-1995 was a pivotal point in engine oil changes. Anyone else remember this?

EDIT: With a bit more head scratching, I think I noticed the actual change in 1996.

 

[Garak]

Originally Posted By: doitmyself
So, yes, 1994-1995 was a pivotal point in engine oil changes. Anyone else remember this?

EDIT: With a bit more head scratching, I think I noticed the actual change in 1996.

Yes, there was a definite fork between the S and C specifications. One can still find some SL and later PCMOs that have a C specification of some sort, usually if it's a 10w-40 or something like that, lacking an ILSAC rating. However, those are older diesel specs, and most oils that could claim such a spec don't even bother any longer. I certainly can't say I've seen a new oil with the Starburst up front along with an older diesel spec in the Donut. Tom, I'm sure, could tell us about this with much more precision.

 

[CharBaby]

Originally Posted By: regal55
Originally Posted By: Char Baby
A little bit more ZDDP was removed between SG to SL and again from SL to SM. SM to SN has remained the same.


timeline ?


Mid to late 90's thru 2011 for all. I don't remember the timeline for each new API spec but, this will give you an idea.