ZDDP Lives On

Joined
Nov 16, 2002
Messages
38,036
Location
NJ
"Engine oil antiwear performance levels have continued to rise over the past couple decades, even as ZDDP levels fell. So what provided this additional performance? For the most part, it was not new additive chemistries as industry insiders had predicted. Numerous organizations researched and sought to develop products, and some were commercialized, but industry insiders say few have been widely deployed. Much of that owes to the multi-faceted usefulness of ZDDP. Cutting back on the chemical affects not only antiwear performance, but also antioxidancy and corrosion inhibition, so multiple parts of a formula need to be adjusted."

"Cost is also an issue. Any significant change in automotive engine oil formulation requires formulators to redo testing to prove performance levels defined by product specifications. Engine tests in such specs can be very expensive, generating bills of millions of dollars—and that’s just if final tests are passed the first time around. The tab increases if you also consider tests conducted during development and if any tests need to be rerun."

"Instead, the lubricant and auto industries found a number of ways to improve antiwear performance with lower levels of the main agent for that performance. For one thing, additive companies found that some varieties of ZDDP are more effective than others. In particular, aryl varieties are slower to form up into a protective film than alkyl varieties. Also, primary alkyl ZDDPs are more volatile than secondary alkyl types, meaning that they tend to evaporate, leading to a decrease in performance."


 
So, what is the bottom line? Are the new oils with the lower ZDDP levels as good as the older ones? Especially for use in older engines with non roller lifters. Stock engines, not high performance.
 
What it's saying is formulators are tasked with doing more with less. It's like having a choice of any tri-tip, filet mignon, ribeye, etc... that you want, as much as you want, and being told you can now only have 1/2" sirloin cuts but the taste better be the same or better. You have to elevate it. You learn new cooking styles, new seasonings, and new methods of preparation to elevate what you're working with. Same concept. The volatility of primary alkyl ZDDP, and poor tribofilm formation of aryl ZDDP, has been known for decades. It's just recently (last couple decades) become more common knowledge (outside of the few chemists involved) as demands for lower concentration and better performance come out with newer standards.
 
The bottom line of that article is that the goal for many formulators is not to replace ZDDP as many people believe, but rather to understand it better. As we've discovered more about it, we've learned how to use it more efficiently than in days past.

That better understanding also provides opportunity to utilize additive synergies more effectively making ZDDP even more useful over time and providing methods to reduce the total amount without sacrificing performance.
 
So then in effect you are saying that the newer, lower, ZDDP formulations do protect the camshafts in older engines as well as the older formulas?
 
So then in effect you are saying that the newer, lower, ZDDP formulations do protect the camshafts in older engines as well as the older formulas?
I can't speak for every new formula out there. I can say that they should perform as well if not better, but that highly depends on what the oil is designed to do. If it is designed to protect camshafts of older engines, then a lower ZDDP content should be irrelevant. If it is designed specifically for newer engine designs and there is no consideration made for the conditions of those older machines, it might not do so well in those applications.

Best thing to do in that case is ask the manufacturer which of their products is best suited for that application.
 
The issue with older flat tappet cams in older V engines is the lifter to lobe interface combined with the weight of the valvetrain. You have pushrod, rocker, and valve weight and spring rate multiplied back across the rocker ratio. The forces create a need for more ZDDP protection that just a better type may not provide on its own. You also have to consider the balancing act of ZDDP and detergents in that anti-wear discussion. Part of the cause for flat tappet failures with ZDDP reduction was a sharp increase in detergents around that same time.
 
The issue with older flat tappet cams in older V engines is the lifter to lobe interface combined with the weight of the valvetrain. ...
Why would that issue be any different for in-line or horizontally-opposed engines?
My old Subaru and Mazda engines used aluminum push-rods and rocker arms, respectively, to limit valvetrain mass.
 
Why would that issue be any different for in-line or horizontally-opposed engines?
My old Subaru and Mazda engines used aluminum push-rods and rocker arms, respectively, to limit valvetrain mass.

The valves are bigger, longer, and heavier. The springs are higher rates. The rocker arms are higher ratio in the 1.5-1.7 range. The pushrods are 7-8" long and made of 5/16-3/8" diameter, .080-.105" wall steel. The cam lobes are typically >.300" lift with small base circles and high acceleration rates with aftermarket cams. I was dealing with an issue just this past weekend of rocker arm and pushrod damage due to deflection of the pushrod jackhammering the valvetrain and that engine was only turning 5500 rpm. Having to upgrade from 5/16" x .080" steel to 3/8" x .110" chromoly to stiffen it enough which means even more weight to sling around.
 
I just bought an OE cam kit from Melling and it comes with an additive to add to the oil for break in and plainly stated the need for ZDDP in the oil for a long happy life. Hard to find higher levels of ZDDP on the bargain shelf at walmart, even the diesel oils. Forces the consumer toward a boutique.
 
The valves are bigger, longer, and heavier. The springs are higher rates. The rocker arms are higher ratio in the 1.5-1.7 range. The pushrods are 7-8" long and made of 5/16-3/8" diameter, .080-.105" wall steel. The cam lobes are typically >.300" lift with small base circles and high acceleration rates with aftermarket cams. ...
Not all "older V engines" were race-oriented.
 
Who said anything about race-oriented? The stock cam in my '85 FSB was .305" lobe lift with just 52 degrees lobe intensity. Hydraulic flat tappet.
 
its all about $$$$$ as profits rule + guessing the thinner oils that generally have less film strength adds to the issue!! buy what works for your engine + DONT worry about minimal MPG increases from watery lighter lubricants!!
 
if you want to play you gotta pay!!! hot rodding older engines or even enhancing modern ones especially if boosted, you can easily increase performance a LOT with DI to control knock, just consider the proper better $$$ oil a part of doing business!! my stock 1.8T jetta with almost double the output ran happily until traded at 200 thou, i used Scamsoil when it was advertised as PAO then Redline until trade, no issues or sludge the engines were known for + i even dumped the free oil changes for use in my girlfriends 99 malibu as VW would not put in the real synthetic i wanted to supply, later on they specd synthetic, a group III for sure but better than whatever they used before.
 
Back
Top