I stumbled across a topic recentley about extending oil change intervals with synthetics, about while a used oil analysis might show low wear metals and such...BUT your engine could be full of sludge!?!? I normally err on the side of caution with what I read on the internet..BUT supposedly this info was quoted by the great terry dyson. I know I once read on the internet about Amsoil recommending their engine flush after a once a year OCI with their products, and am now starting to wonder?? I would sure like to see inside of some certain member's engines on this forum who have ran greatly extended intervals on any synthetic lube. I know I am going to get flamed by amsoil user's...but I can "take it on the chin" until I am proved otherwise...with pics perhaps?? FIRE AWAY at me if you will...I will check back in a few days!!
Extended OCI's and SLUDGE with good UOA's??
- Thread starter Ponch
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I would never run oil in my car past. 6000 miles that would be a stretch for me to. Overk1ll had a picture under the valve cover of a 302 with 7500 oci with Mobil 1 was spotless. But that 15,000 or 25,000 is crazy IMO . You should get under your car and have a look see more often than that and what better time to do so then when changing oil.
As far as I remember, Mercedes engines in early 2000's had sludge problem when drivers used conventional oil with OCI up to 15k miles according to FSS (MB OLM), drivers used synthetic (Mobil 1 0W40 was recommended) didn't have any problem with sludge.
I wouldn't use conventional oil passes 7-8k miles OCI, but have no problem using syn oil passes 12k miles.
I wouldn't use conventional oil passes 7-8k miles OCI, but have no problem using syn oil passes 12k miles.
The UOA will show oxidation and insolubles, both of which will form sludge. If these and the other items on the lab report are good, I'd feel OK.
If quality oils are used paired with good oil and air filters to keep the engine clean and the OCIs are within factory recommended (or supported by UOA) limits, i think the engine should be spotless after a lifetime of long OCIs.
I post pics of how clean the top of the engine is in my 07 Civic EX 1.8L in a few months. It has seen OCIs range from 7-10k for the past few years with Mobil 1 Extended Performance and most recently Amsoil oils.
I post pics of how clean the top of the engine is in my 07 Civic EX 1.8L in a few months. It has seen OCIs range from 7-10k for the past few years with Mobil 1 Extended Performance and most recently Amsoil oils.
dnewton3
Staff member
The internet is like anything else; it's only as good as the stuff put into it. (Yes - there is irony in my statement; I recongnize that.)
If extended OCIs are such a bad idea, why do many top-tier lube companies advocate them? It would be in their best interest (from a fiscal/sales point of view) to have the lowest OCI tolerable, would it not? And yet companies like Amsoil and Castrol (among many others) tout extended OCIs.
Of note (and yes, this is targeted to large OTR rigs) I'd call out the example of 70k mile OCIs (yes, that's seventy-thousand miles!) for the Castrol Hypuron semi-syn in 10w30 (NOT the 15w40, which is "only" rated for 50k miles).
http://www.castrol.com/castrol/sectiongenericarticle.do?categoryId=9039290&contentId=7071985
They only mention the need for used oil analysis along the way; no requirement of a high-end bypass filter. Of course, the "better" the filtration, the longer the oil is going to last. But as you can see, Castrol has two semi-syns that are 50k and 70k mile capable. Do you think that Castrol would risk their reputation in the big-rig market with just a willy-nilly notion? Or, do you suppose they actually studied their products in real life applications? I'm going with the later ...
Amsoil is also a well-proven long OCI product. Most all of their products are 3x the OEM OCI, with no bypass and no used oil analysis. Only past that 3x factor do you need to use used oil analysis. Do you suppose they would stake their reputation on sludge? I find that impratical for them. They rely on their excellent reputation. They could not afford a sludge scandal (nor could any lube maker, for that matter).
When CJ-4 lubes first came out, there was a large backlash regarding the "lower" additive packages; the fear was that wear was going to be acelerated. But what many over-looked was the excellent boost in dispersents and detergents to combat the use of EGR. In reality, wear is well under control; soot/insolubles are well in control. It was a "win-win" all around. All the major lube makers did (collectively) millions of miles of studies. If sludge were an issue (an any given OCI duration) they would limit their product to some value lower than that OCI, would they not?
I would certainly agree that one has to know the complete picture of the operational campaign. Evnirnomental, serverity, filters, lubes, etc, etc, etc. You cannot throw a blanket over such a specific topic like extended OCIs and say "Yes - it's OK for all" or "No - it's never OK" because each situation is unique.
ANY lube, regardless of base stock, can be over-utilized or under-utilized. To run any lube to a point where the oxidation and insolubles are out of control is foolish. But just extending the OCI does not assure that is to happen. And, if the oxidation/insolubles are tracked diligently, you can avoid this and watch for the onset, long before a danger point is touched.
Some people are not comfortable with exended OCIs; fine by me. They must manage their maintenance program the way they see fit. Often, it is a huge waste to OCI by the odometer. In fact, it could be just as dangerours to use that OEM OCI; it could be (conceivably) too long. After all - how do they know what you do with your equipment? Now the reality is that they are very conservative in their OEM OCI limits; the equipment makers don't want a warranty issue or a law-suit (as some are aware of the infamous Toyota sludge issues, or the Saturn ring-cokers, among others). My point? Even "standard" OEM OCIs can occasionally produce conditions that would sludge/coke up your ride. In this case the OEM OCI was apparently "extended" too far, right? And, I'm not sure how obvious the sludge would have been at first. It's not like it just happens immediately in one OCI.
Soot/insolubles/oxidation can most certainly be tracked and trended in a used oil analysis. Will is assure 100% knowledge of everything? No. But it you want that kind of knowledge, you'll have to do a "preventative maintenance" engine tear-down and rebuild annually to "know with absolution" how the lube is combating sludge and wear. That sound feasible for the common man? Is it reasonable to think that each of us here is going to take a weeks vacation, pull the engine out of our car/truck, do a total teardown to the block and bearings, just to track sludge? Now, you can "hedge your bet" by popping off a valve cover, but it's not going to tell you how the rings are doing.
Should one extend the OCI hap-hazzardly? NO!
Can one extend the OCI with a pre-planned approach, tracking all applicable parametrs with all available tools, gleaning information and making rational decisions viewed against reasonable condemnation limits? YES!
Like everything else, it's up to the individual to define and implement his/her approach.
If extended OCIs are such a bad idea, why do many top-tier lube companies advocate them? It would be in their best interest (from a fiscal/sales point of view) to have the lowest OCI tolerable, would it not? And yet companies like Amsoil and Castrol (among many others) tout extended OCIs.
Of note (and yes, this is targeted to large OTR rigs) I'd call out the example of 70k mile OCIs (yes, that's seventy-thousand miles!) for the Castrol Hypuron semi-syn in 10w30 (NOT the 15w40, which is "only" rated for 50k miles).
http://www.castrol.com/castrol/sectiongenericarticle.do?categoryId=9039290&contentId=7071985
They only mention the need for used oil analysis along the way; no requirement of a high-end bypass filter. Of course, the "better" the filtration, the longer the oil is going to last. But as you can see, Castrol has two semi-syns that are 50k and 70k mile capable. Do you think that Castrol would risk their reputation in the big-rig market with just a willy-nilly notion? Or, do you suppose they actually studied their products in real life applications? I'm going with the later ...
Amsoil is also a well-proven long OCI product. Most all of their products are 3x the OEM OCI, with no bypass and no used oil analysis. Only past that 3x factor do you need to use used oil analysis. Do you suppose they would stake their reputation on sludge? I find that impratical for them. They rely on their excellent reputation. They could not afford a sludge scandal (nor could any lube maker, for that matter).
When CJ-4 lubes first came out, there was a large backlash regarding the "lower" additive packages; the fear was that wear was going to be acelerated. But what many over-looked was the excellent boost in dispersents and detergents to combat the use of EGR. In reality, wear is well under control; soot/insolubles are well in control. It was a "win-win" all around. All the major lube makers did (collectively) millions of miles of studies. If sludge were an issue (an any given OCI duration) they would limit their product to some value lower than that OCI, would they not?
I would certainly agree that one has to know the complete picture of the operational campaign. Evnirnomental, serverity, filters, lubes, etc, etc, etc. You cannot throw a blanket over such a specific topic like extended OCIs and say "Yes - it's OK for all" or "No - it's never OK" because each situation is unique.
ANY lube, regardless of base stock, can be over-utilized or under-utilized. To run any lube to a point where the oxidation and insolubles are out of control is foolish. But just extending the OCI does not assure that is to happen. And, if the oxidation/insolubles are tracked diligently, you can avoid this and watch for the onset, long before a danger point is touched.
Some people are not comfortable with exended OCIs; fine by me. They must manage their maintenance program the way they see fit. Often, it is a huge waste to OCI by the odometer. In fact, it could be just as dangerours to use that OEM OCI; it could be (conceivably) too long. After all - how do they know what you do with your equipment? Now the reality is that they are very conservative in their OEM OCI limits; the equipment makers don't want a warranty issue or a law-suit (as some are aware of the infamous Toyota sludge issues, or the Saturn ring-cokers, among others). My point? Even "standard" OEM OCIs can occasionally produce conditions that would sludge/coke up your ride. In this case the OEM OCI was apparently "extended" too far, right? And, I'm not sure how obvious the sludge would have been at first. It's not like it just happens immediately in one OCI.
Soot/insolubles/oxidation can most certainly be tracked and trended in a used oil analysis. Will is assure 100% knowledge of everything? No. But it you want that kind of knowledge, you'll have to do a "preventative maintenance" engine tear-down and rebuild annually to "know with absolution" how the lube is combating sludge and wear. That sound feasible for the common man? Is it reasonable to think that each of us here is going to take a weeks vacation, pull the engine out of our car/truck, do a total teardown to the block and bearings, just to track sludge? Now, you can "hedge your bet" by popping off a valve cover, but it's not going to tell you how the rings are doing.
Should one extend the OCI hap-hazzardly? NO!
Can one extend the OCI with a pre-planned approach, tracking all applicable parametrs with all available tools, gleaning information and making rational decisions viewed against reasonable condemnation limits? YES!
Like everything else, it's up to the individual to define and implement his/her approach.
Last edited:
Originally Posted By: Ponch
I know I once read on the internet about Amsoil recommending their engine flush after a once a year OCI with their products, and am now starting to wonder??
Can you post a source for this?
Here's what Amsoil says:
Quote:
Directions for Use
Though it works in one treatment, AMSOIL Engine and Transmission Flush is safe enough to be used at every oil change.
These are two different things, really.
I know I once read on the internet about Amsoil recommending their engine flush after a once a year OCI with their products, and am now starting to wonder??
Can you post a source for this?
Here's what Amsoil says:
Quote:
Directions for Use
Though it works in one treatment, AMSOIL Engine and Transmission Flush is safe enough to be used at every oil change.
These are two different things, really.
Beyond certain engines with design issues, sludge is often found according to the duty cycle of the engine. You don't often see engines that run long hours and long OCIs with sludge (as with Dave's OTR truck example) but you more often see short hoppers with it. The answer is an OCI designed for the way the vehicle is driven. And a lubricant that compliments those things. Everybody keeps looking for absolutes in this area of discussion... but there are darn few of them.
Pablo, I have no source to post..as I read this statement years ago. I remember being confused on why they would recommend their engine flush after a 25,000 mile run. I called their tech dept, and spoke with a different person on 3 different occasions NOT only about this subject, but about different issues/concerns and got a different answer from each individual.
Now that I think back about it almost 7 years ago...I remember my other concerns/reasons for calling their tech dept. "Why is this top of the line series 2000 0W30 oil which is supposed to last 35,000 miles or one year coming back with elevated levels of oxidation/nitration/ AND why has this thickened into a 40 weight oil after only 13,000 miles??" They tried to blame everything on a "problem" with my perfectly running vehicle. EGR valve? etc... I tried different formulations of their oils with the same results!
Originally Posted By: Jim Allen
Beyond certain engines with design issues, sludge is often found according to the duty cycle of the engine. You don't often see engines that run long hours and long OCIs with sludge (as with Dave's OTR truck example) but you more often see short hoppers with it. The answer is an OCI designed for the way the vehicle is driven. And a lubricant that compliments those things. Everybody keeps looking for absolutes in this area of discussion... but there are darn few of them.
^This. +1
Beyond certain engines with design issues, sludge is often found according to the duty cycle of the engine. You don't often see engines that run long hours and long OCIs with sludge (as with Dave's OTR truck example) but you more often see short hoppers with it. The answer is an OCI designed for the way the vehicle is driven. And a lubricant that compliments those things. Everybody keeps looking for absolutes in this area of discussion... but there are darn few of them.
^This. +1
Hï,
dnewton3 - Regarding Castrol's long OCI semi-synthetics in OTR trucks you said this:
"Or, do you suppose they actually studied their products in "real life applications? I'm going with the later ..."
I can reassure you that this was (and still is) the case. I was heavily involved in this programme during the early 1990s. Their US engine product then was finally labelled as Enduro (LD) a 15w40 viscosity (CF-4, max Ash levels 1.5%) and doubled the engine Manufacturers OCI (Castrol's recommendation) from 20kkms (12k miles) to 40kkms (25k miles)
In parallel testing I can confirm this over their highest rated mineral 15w40 HDEO of the time
I never got their mineral HDEO beyong about 20kkms before the lubricant was unservicable
I took the prototype lubricant out to 50kkms many many times during testing the various formulations and again soot levels of around 3% finally condemned further use
Soot handling is a huge factor of additive package design and I later tested/used a more sophisticated product from another Oil Co that enabled up to around 7% soot levels at the upper point (not continuous use)!
IME it is the use of inferior classed products (not correct for the engine family) that promote sludge in diesel engines
This has almost invariably been the case in the engines I've inspected - typically when under warranty too!!
dnewton3 - Regarding Castrol's long OCI semi-synthetics in OTR trucks you said this:
"Or, do you suppose they actually studied their products in "real life applications? I'm going with the later ..."
I can reassure you that this was (and still is) the case. I was heavily involved in this programme during the early 1990s. Their US engine product then was finally labelled as Enduro (LD) a 15w40 viscosity (CF-4, max Ash levels 1.5%) and doubled the engine Manufacturers OCI (Castrol's recommendation) from 20kkms (12k miles) to 40kkms (25k miles)
In parallel testing I can confirm this over their highest rated mineral 15w40 HDEO of the time
I never got their mineral HDEO beyong about 20kkms before the lubricant was unservicable
I took the prototype lubricant out to 50kkms many many times during testing the various formulations and again soot levels of around 3% finally condemned further use
Soot handling is a huge factor of additive package design and I later tested/used a more sophisticated product from another Oil Co that enabled up to around 7% soot levels at the upper point (not continuous use)!
IME it is the use of inferior classed products (not correct for the engine family) that promote sludge in diesel engines
This has almost invariably been the case in the engines I've inspected - typically when under warranty too!!
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