Oil Strategy To Prevent Carbon Piston / Ring Deposits ?

[buster]

Having over 400K miles on my Xterra all on conventional or blend, with no oil usage at all, I have concluded it’s mostly engine design.

Having said that I have decided to run low SAPS euro oil in everything else including my Toyota going forward. Whether that helps or not

Agree. I'm hoping we see better engines going forward now that CAFE is gone.

 

[4wd]

This is likely the only site where the well used entry level car gets good motor oil every time. Think of folks living paycheck to paycheck - buy a used economy car only to find it eats oil. So while grabbing two of the latest scratch off’s that’s gonna dig them out of the hole - also grab a quart of Golden State. I have watched this sad scene for years …

 

[Cousin Vinny]

• Good base oils—GTL / PAO / Esters
• Relatively high viscosities—30-40 grade with Euro car approvals
• 5,000 to 7,500 miles oil change intervals (depending on engine type, driving style and conditions)

I was going to suggest, driving it like you stole it and Italian Tune-Ups (go full throttle about once every trip, if possible) should keep deposits from being formed.

I hope the suggestion is to use Shell, in the appropriate octane for the car, not Premium (93 Octane) for everything...

 

[Cousin Vinny]

This is likely the only site where the well used entry level car gets good motor oil every time. Think of folks living paycheck to paycheck - buy a used economy car only to find it eats oil. So while grabbing two of the latest scratch off’s that’s gonna dig them out of the hole - also grab a quart of Golden State. I have watched this sad scene for years …

Yeah, when I saw motor oil at Dollar General I cringed a little bit.

The plot twist, is, that has the Starburst on it as well...

 

[SC Maintenance]

Agree. I'm hoping we see better engines going forward now that CAFE is gone.

I agree CAFE is nothing positive, however there was plenty of crap built before CAFE, and I doubt it’s gone anyway. CAFE is an EPA rule not a law of congress. It can change with the next guy just as easily.

 

[buster]

I agree CAFE is nothing positive, however there was plenty of crap built before CAFE, and I doubt it’s gone anyway. CAFE is an EPA rule not a law of congress. It can change with the next guy just as easily.

True

 

[rstsco]

I hope the suggestion is to use Shell, in the appropriate octane for the car, not Premium (93 Octane) for everything...

My choice to use Shell premium is based on the higher concentration of additives, and types of additives, vs those used in their 87-octane, regular gasoline. Even though it will run okay on 87-octane, even my wife could tell the difference from using regular vs premium. The Pilot likes the premium and I'm willing to pay the difference. YMMV.

 

[OVERKILL]

Isn't this showing that running AMSOIL for 2x the test duration starting to develop minor deposits, but runs clean at the original test duration - so the best option would be to use an oil like AMSOIL but *not* extend OCIs?

You have to consider the conditions of the test. Think of it like running a 5,000 mile interval towing the entire time, without an oil cooler. It's designed to speed up the degradation of the oil (create oxidative thickening, consumption and deposits), not be representative of operating conditions experienced during a standard OCI. As @buster pointed out, the most concerning piece of data is that many/most oils barely pass, as he notes. But then, we are talking products where the focus is blending to a price point, right?

The takeaway, in my mind is that product choice can have a considerable impact on piston cleanliness in service, as can engine design. If you've got an engine that produces more demanding conditions than the Pentastar (eg, a TGDI mill with a small sump that you flog), looking at better lubricants may be in your best interest, as would perhaps getting a few UOA's done to track oxidation. These are applications that may also be sensitive to drain intervals, due to how they beat up the oil, and subsequently, to @oil pan 4's point, not be tolerant of neglect or abuse.

If one was feeling creative, you could likely turn this into a venn diagram.

 

[OVERKILL]

I was going to suggest, driving it like you stole it and Italian Tune-Ups (go full throttle about once every trip, if possible) should keep deposits from being formed.

I hope the suggestion is to use Shell, in the appropriate octane for the car, not Premium (93 Octane) for everything...

I think the argument for higher octane with the TGDI/GDI mills is to reduce fuel dilution, as enrichment is used to mitigate knock, and some designs may be leaning more on this than others.

 

[oil pan 4]

Kind of. It's designed to expedite the aging of the oil, by running it at a higher temperature (150C, the temperature we run HTHS at), but the application (Chrysler Pentastar) is naturally aspirated and port injected, so not the most demanding. The test is designed to measure the oil's propensity to create piston deposits (and the conditions encourage them). The previous version, IIIG was effectively the same test, but run with a GM 3.8L engine.

The test lasts 90 hours, run at 3,600rpm at about 45% full power (137hp). We could use the hours to rough-out a mileage equivalent estimate (eg, 5,000 miles at an average speed of 55mph), but we might be best comparing it to something like towing, driving up oil temp and moderately increased load.

This was a pass with IIIG:
View attachment 348776

This is a pass with IIIH:
View attachment 348775

Now, I'm sure we can agree that 90 hours (5,000 miles of towing at 55mph?) isn't a long/extended OCI.

This is what @buster shared from AMSOIL:
View attachment 348777

Which I think does a good job illustrating how a higher quality oil can make a considerable difference here. AMSOIL at 180 hours (twice the drain interval) is still significantly cleaner than our "reference oil", or the "pass" above.

In the past, both Mobil and Pennzoil have posted IIIG pictures to show how much better than a "pass" their oils do in this sequence. Of course Valvoline is also using a variation of this same sequence to show how Valvoline Restore and Protect is able to remove deposits.

So, @Patman noted, oil selection clearly plays a role. There is a considerable difference between an oil that just passes the test and one that massively out-performs the requirements.

However, as I said, the Pentastar isn't a challenging application. Dealerships aren't pulling them apart due to oil consumption. A more representative example would be a low displacement TGDI mill with a baby sump, ones where we've seen cases of oil consumption.

The piston you shared showed generous land area, somewhat similar to the Pentastar and GM 3.8L pistons. I doubt it regularly saw 150C oil temps, am I right?

Look at how narrow the oil control land (with a stuck ring) is on this Toyota piston in comparison:
View attachment 348781

Now add a turbo and DI washing the bores down with fuel, torpedoing the oil film's volatility resistance.

So yes, engine design also plays a considerable role.

There are applications, like the Toyota 2.5, and the Honda 3.5L VCM engine that no matter how frequently you change the oil, the pistons rings cake up with deposits and oil burning starts, underscoring that short-changing is not some universal panacea. This is not neglect or abuse, it's engineering choices manifest, coupled with the unwillingness to address this through a specification or approval. Highlighting that further: this same trend has been mitigated, in many instances, by the use of better oils, like Mobil 1 0W-40 in the aforementioned Honda mills.

And yes, of course, if oil is left in service beyond the point where it's DI package is able to do its job, you will also get deposits (your neglect/abuse argument). But, depending on the application, the point at which that takes place will vary wildly.

So short changing Supertech for example, in an application that isn't easy on oil, can result in more deposits than longer drains on Mobil 1 or AMSOIL.

And yes, choice of lubricant can absolutely dictate whether you get ring coking or not, regardless of the OCI length. And this is dictated by the mechanical and operational characteristics of the engine. An application that is harder on oil may require a better lubricant.

Also worth mentioning:

Thinner oils are allowed more deposits. For SQ, xW-20 and above must be 4.6 merits or above. 0W-16 is 4.2, 0W-8/0W-12? 3.7.

My Honda piston in that pic had hundreds of hours on it and didn't have an easy life. The only break it got was the guy who used it for the 15 years before I had it I bet he changed the oil at least a dozen times on it, probably closer to 20 times.
Only reason that Honda went bad was one of the times he changed the air filter, the oring that's supposed to be under the airfilter to seal out the dirt went in the trash with the old filter. Probably been like that most of the 15 years he had it.

A quick Google image search shows piston skirt temperatures between 106c which seems low and 142c. My guess would be the 106c skirt piston is idling or normal driving and the 142c piston is peak temperature on a dyno beat down based on how hot the crown is on the respective chart, with the hotter piston being about a full 100c hotter up top.

I think 90hrs towing with the overdrive disabled even 50% of the time would be more like super extreme duty. Probably should change the oil around 3,000 miles, 120 to 80hrs. Maybe even more often but thats a hard sell to most people. Most vehicles I've looked at the average miles per hour of run time fell between 25 and 35 mph with very few exceptions.
With those exceptions being things like cop car and usps delivery on the low end (and they're probably never towing). Things like hotshot trucking, car haulers and rental vehicles on the high end where they definitely could see some towing. If you're driving commercially that's an oil change every few weeks.

I figure things like Valvoline Restore and Protect, Pennzoil Ultra Platinum, Pennzoil Platinum, most of not all mobil1 oils will produce very good to great III series tests and oils like HPL, amsoil, driven to produce excellent and outstanding results even on modified III tests with added run time.
Its pretty clear that more time makes the test a lot worse.
I'm more interested in the III G and H test naughty list.
What makes an oil do a bad IIIG or IIIH test result?
If its a bad IIIG test, does that oil even exist anymore?
Say someone runs 5 year old oil Pennzoil Platinum the oil is oxidized out and a bunch of the additives settled on the bottom of the jug, thats probably not ideal. Kinda hard to test too and a bit pointless other than as an academic exercise. It would be kinda like running or testing SA or ND oil, you know it's going to be bad and its easy to avoid.
Let's say a bottom rung oil like 5,000mi Supertech? What's that do?
Is it price a determining factor? If so then I'd love to see what $13 a gallon (old price) delvac 15w-40 could do, don't think it would ever happen for obvious reasons.
Is it a thing found more with old oil ratings like SH, SJ, SL or SM rated oils?
Can SL oil even be found anymore? I don't think if seen an SL rated oil, where SL was the top rating on the oil in the last 15 years.
I don't think we need to see SA or ND oil tested, those are a bit harder to find and no one should be filling up their car with that kind of oil. I'd be shocked if they weren't anything but absolutely terrible if tested.

Another point for thicker is better at the end there?
Also, wow it almost seems like they're betting on the engines not lasting as long with the thinner oil....
I dont remember reading that part about the thinner III series test oils being allowed to produce dirtier results. You just made my day.

 

[buster]

Take this for what's worth which may be nothing. On another forum a former Chevron engineer seems to think that esterless oils (majority off off shelf oils) don't do as good of a job at keeping engines clean. Mobil around the year 2000 was looking for away to reduce or get rid of esters in their oils. George from AV Lube mentioned it was due to cost, but also newer additives coming online.

He refers to these oils as "dry" and relying just on oxidation resistance to keep engines clean. Whether this is true or not is anyone's guess.

Take a look at the Mobil 1 line and you'll notice a pattern, even with Amsoil. Mobil saves the POE for their top shelf products as does Amsoil. Amsoil OE/XL have a virgin oxidation of about 8 where as AMSOIL Signature Series and Dominator are 40-60. Only HPL and RL seem to go full out across all lines, which is pretty cool.

If some of these off shelf oils barely pass the IIIH I would certainly not run them for long. I'd cut intervals down drastically if you're going to keep the vehicle.

 

[oil pan 4]

So true. Those engines are tough on oil. Actually they'd be interesting candidates to test oils in.

I don't know how I feel now that I know most oils barely pass the IIIH according to Amsoil.

In that EE video there are some piston photos but they don't specifically show a Mobil 1 piston. For off the shelf I think Mobil 1 would likely do the best in the IIIH.

My thinking for Valvoline Restore and Protect is it will leave deposits when pushed super hard, but will also actively clean once temps fall back down. So theoretically you could run Valvoline Restore and Protect in a IIIH and come out with dirtier pistons than Amsoil. However, once temperatures fall back down to normal levels, Valvoline Restore and Protect would clean them up. Or Valvoline Restore and Protect is so good it won't leave any deposits but it will eventually break at some point and I think the IIIH would break it.

In other words, the SWRI lab basically gave credibility that Amsoil does make the most thermally stable oil.

My observation is Valvoline Restore and Protect seemed like it was barely doing anything until I took it on multiple road trips that involved some towing. Then I saw a dramatic increase in filter sludge.

 

[oil pan 4]

If some of these off shelf oils barely pass the IIIH I would certainly not run them for long. I'd cut intervals down drastically if you're going to keep the vevehicle.

On my wifes car I found that I couldn't go anywhere near the recommended oci of 7,500mi according to test results.
I couldn't use better oil like amsoil or hpl due to fuel dilution. I could but I would be wasting it. Just her driving the car it needed 3,000 to 4,500 mile oil changes due to fuel dilution.
Diving on the highway more and running "sport mode" so the car didn't turn off at every single stop or slow down helped, added at least a thousand miles to my oci but the Pennzoil Platinum and Pennzoil Ultra Platinum I used still suffered from viscosity breakdown.
The major fix for viscosity breakdown was use 10w-30 Pennzoil Platinum or Pennzoil Ultra Platinum just past the low mark and slowly top off the oil with 20w-50 over the life of the oci.

 

[userfriendly]

15W-40

 

[buster]

My observation is VRP seemed like it was barely doing anything until I took it on multiple road trips that involved some towing. Then I saw a dramatic increase in filter sludge.

It does need heat to work well. I think if you're driving around town on short trips where the oil likely never gets above 150F it will take a very long time.

 

[OVERKILL]

My Honda piston in that pic had hundreds of hours on it and didn't have an easy life. The only break it got was the guy who used it for the 15 years before I had it I bet he changed the oil at least a dozen times on it, probably closer to 20 times.
Only reason that Honda went bad was one of the times he changed the air filter, the oring that's supposed to be under the airfilter to seal out the dirt went in the trash with the old filter. Probably been like that most of the 15 years he had it.

A quick Google image search shows piston skirt temperatures between 106c which seems low and 142c. My guess would be the 106c skirt piston is idling or normal driving and the 142c piston is peak temperature on a dyno beat down based on how hot the crown is on the respective chart, with the hotter piston being about a full 100c hotter up top.

I think 90hrs towing with the overdrive disabled even 50% of the time would be more like super extreme duty. Probably should change the oil around 3,000 miles, 120 to 80hrs. Maybe even more often but thats a hard sell to most people. Most vehicles I've looked at the average miles per hour of run time fell between 25 and 35 mph with very few exceptions.
With those exceptions being things like cop car and usps delivery on the low end (and they're probably never towing). Things like hotshot trucking, car haulers and rental vehicles on the high end where they definitely could see some towing. If you're driving commercially that's an oil change every few weeks.

I figure things like VRP, PUP, PP, most of not all mobil1 oils will produce very good to great III series tests and oils like HPL, amsoil, driven to produce excellent and outstanding results even on modified III tests with added run time.
Its pretty clear that more time makes the test a lot worse.
I'm more interested in the III G and H test naughty list.
What makes an oil do a bad IIIG or IIIH test result?
If its a bad IIIG test, does that oil even exist anymore?
Say someone runs 5 year old oil PP the oil is oxidized out and a bunch of the additives settled on the bottom of the jug, thats probably not ideal. Kinda hard to test too and a bit pointless other than as an academic exercise. It would be kinda like running or testing SA or ND oil, you know it's going to be bad and its easy to avoid.
Let's say a bottom rung oil like 5,000mi Supertech? What's that do?
Is it price a determining factor? If so then I'd love to see what $13 a gallon (old price) delvac 15w-40 could do, don't think it would ever happen for obvious reasons.
Is it a thing found more with old oil ratings like SH, SJ, SL or SM rated oils?
Can SL oil even be found anymore? I don't think if seen an SL rated oil, where SL was the top rating on the oil in the last 15 years.
I don't think we need to see SA or ND oil tested, those are a bit harder to find and no one should be filling up their car with that kind of oil. I'd be shocked if they weren't anything but absolutely terrible if tested.

Another point for thicker is better at the end there?
Also, wow it almost seems like they're betting on the engines not lasting as long with the thinner oil....
I dont remember reading that part about the thinner III series test oils being allowed to produce dirtier results. You just made my day.

Thanks for your feedback.

Yes, piston temps are certainly a factor in real-world use, but we need to keep in mind that with this test, it's bulk oil temps that are elevated to 150C, to prematurely degrade the oil. Bulk oil temps on my SRT are around 104C, so even if the oil gets much hotter in the land area, it's only there for a brief period of time, and then gets a "rest". I do wonder if when somebody like Toyota blindly spec's 10,000 mile intervals, it's loosely based on anticipated performance extrapolated back from extremes in tests like these with a fudge factor, because of course they don't have an OEM test and approval program that mandates a minimum level of performance in their products. Given that this test is done on a naturally aspirated port-injected engine, it may work to explain, at least in part, why people like CCN are seeing ring sticking and coking on the spec oils at the spec intervals in some of these TGDI engines, an issue compounded by the use of extremely thin oils that aren't held to the same standard as heavier ones.

IIIG was the standard up through SN. When SOPUS first introduced their GTL-based oils, they were tested with IIIG, same with Mobil's VISOM slides for their Euro 0W-40, so I think performance on it is still relevant. SL used IIIF, the details for which I haven't looked up.

And yes, exactly what I was getting at with the lower rung oils, if you are using those in demanding applications under adverse conditions, OCI length may have no real impact on ring land deposit formation (like the Honda VCM V6), you may have to actually step-up to a better oil to avoid coking and consumption as the miles pile on.

 

[OVERKILL]

My observation is VRP seemed like it was barely doing anything until I took it on multiple road trips that involved some towing. Then I saw a dramatic increase in filter sludge.

Heat may be a factor, as @buster noted, but I would also think that cylinder pressure increase, as a result of increased load produced during towing, may have helped, putting more pressure behind the rings, perhaps forcing some movement that helped the product liberate some material that was in there.

 

[theMM]

The others have already mentioned it in regards to the oil, but I'm surprised no one has mentioned this yet regarding the fuel you use, but doing an "Italian tuneup" actually does help in regard to blowing out the carbon, and helps clean the injector tips in DI engines. It also helps reduce some carbon deposits on the piston. Proof? DIYAutoWorksNG on YouTube has 3 separate videos testing this with and without fuel additives and has side by side comparison using a bore scope.. I would also go with whatever Premium fuel offering that offers more additive package in their premium grade 91/93 versus their regular 87 offering, unless you use Costco fuel or other brand of fuel that is known to have the same amount of additives in all 3 grades. I like BP's 93 for example, especially now since they are Top Tier Plus rated.

 

[JunkdrawerDog]

I bought a Honda HRV that is normally aspirated and port fuel injected. I run Chevron 87 octane almost exclusively. I change oil annually at ~3000 miles. Let the chips fall where they may!

 

[Boge60]

...My thinking for Valvoline Restore and Protect is it will leave deposits when pushed super hard, but will also actively clean once temps fall back down. So theoretically you could run Valvoline Restore and Protect in a IIIH and come out with dirtier pistons than Amsoil. However, once temperatures fall back down to normal levels, Valvoline Restore and Protect would clean them up. Or Valvoline Restore and Protect is so good it won't leave any deposits but it will eventually break at some point and I think the IIIH would break it...

Lake Speed Jr. said VRP works better at higher ambient temps and long trips at higher speed.

He also stated in an Amsoil test that there is no 'best' motor oil, but rather best oils for specific scenarios. It us up to you the consumer to determine which one that is.