dnewton3
Staff member
I would ask that you define "more beneficial" specifically.I am ignoring some of the statements made like," that sludge'l getcha everytime", but I agree with the statement made tangentially by Bill7.
A shorter OCI will be seen to be more beneficial over a long (10k or more ) over all engines, oils, climates, usage patterns, etc. (all variables combined). If one could combine all the engines in the world and log all these factors. I don't think anyone can reasonably argue with that. The best case to be made for a long OCI is that it doesn't do harm vs a shorter one, not that it is superior in some way. The reverse is true for a short OCI. The bias for a superior schedule lies with the shorter OCI, across all variables. I don't think that is arguable.
I'm not in agreement with your statement, but I'm willing to hear you out.
I say this because I have wear data (wear rates and wear trends) from about 35,000 UOAs in my database. I can tell you the general trend in wear rates indicates that, overall, there is benefit to running a longer OCI. The wear rates drop in pretty much every single engine series I've ever studied.
Further, the data I have also indicates that contamination (soot, oxidation, coolant, silica, fuel) are parameters which must be monitored, but they do not become obscenely invasive as long as the systems are operating properly. When some form of contamination is present in an undesirable level, then that system needs addressed.
The "superior" aspect of longer OCIs is
- it is a cost savings
- it does, most frequently, result in a lower wear rate out to 15k miles (my data stops there, so I cannot attest to what the phenomenon exhibits past that point)
I will define OCI durations:
* short = 5k miles or less
* moderate = 5-10k miles
* extended = greater than 10k miles
There are always exceptions to the rule. Some infamous engines such as the Toyota's which sludged up; the Saturn SL2s which had no drain-back relief in the piston rings. But those are isolated in grand scheme of things.
The debate comes from this concept ...
When someone says some duration of OCI is "better" or "worse" than another, it's best to ask "Relative to what?"
Some people say a 5k mile OCI is "best". OK - best at what? If one does not measure objective parameters, then only subjective opinions prevail. I prefer to look at real world data. If "short" OCIs are "best", then would super short OCIs be even better than best? Would a 4k mile OCI be "better" than a 5k mile OCI? If that's true, would 3k miles be better than 4k miles? Why not 2k miles? Is a 1k mile OCI optimum???????
As I said, I disagree with you assessment, but I'm willing to hear you out. Please put up the data which supports your side of the debate. All the data I have (thousands upon thousands of UOAs) points toward longer OCIs being generally of benefit in that they not only save money, but result in lower wear rates, all while not risking severe contamination; this data exists across nearly all engine series I've ever studied with rare exception. See this for a rudimentary example:
Used Oil Analysis: How to decide what is normal - Bob is the Oil Guy
Reviewing UOA Data Used oil analyses (UOAs) are tools. And like most tools, they can either be properly used or misused, depending upon the application, the user, the surrounding conditions, etc.= There are already many good articles and publications in existence that tell us how to interpret...
bobistheoilguy.com
If you want to speak to specific engine series, let me know what you're interested in and I can see if it's one of the many I have in my study data.