Educate me on 0w40 please

[ZeeOSix]

Originally Posted by Gokhan
Back to ZeeOSix's very interesting and useful study:

Turbo gasoline direct injection (TGDI) engine-wear test development (January 2018)

It's interesting that people always talk about bearings when they talk thin vs. thick oil but neither 0W-16 not 5W-30 had no wear on bearings whatsoever in any driving condition. This is in contrast to BMW M3 bearings, which they quickly fail even with 10W-60.


BMW's problem in that case was most likely an oiling system and/or bearing design and/or clearances issue.

Originally Posted by Gokhan
However, the questions of piston rings and the effect of viscosity on them remains. As piston rings operate on all lubrication regimes (boundary, mixed, and hydrodynamic), it's very complicated, especially for different driving conditions. Neither thin nor thick seems to provide full protection in all driving conditions.


There has been other study data posted in this forum in the past that also showed that a higher HTHS oil helped reduce cylinder and ring wear.

Originally Posted by Gokhan
There were some caveats with the study, such as absence of an oil filter, broken chromium segment of a ring, and leaked intercooler fluid in the cylinder.


I already mentioned that if an oil filter was used it would have skewed the wear data because it would have removed actual wear particles which is what they were trying to measure. So it makes complete sense that they ran the testing without an oil filter. They were looking for total wear, not trying to keep the oil clean.

As far as the slight ring chromium layer shedding and the inter-cooler leak ... they don't think it hurt the collected wear data.

 

[ka9mnx]

Just watched a tube video from GM (2014) discussing the "new" Dexos1 Gen2. The narrator stated that engine oil was not the cause of LSPI. Engine design and controls (ecu mapping) were the primary causes. Once LSPI occurs, oil can facilitate with the problem. I guess this is why some engines are prone while others are not. The new Dexos oil was primarily designed around fuel economy with robustness (for long drains), engine protection and emissions coming in next. It was interesting that she said for Xw20 and Xw16 the engine must be designed around these oils. She said you cannot just do a blanket recommendation for it's use. Like Ford did in my case.

 

[Gokhan]

Originally Posted by ZeeOSix
As far as the slight ring chromium layer shedding and the inter-cooler leak ... they don't think it hurt the collected wear data.

5 - 6 mm (1/4 in) section of the chromium insert was broken. That's not slight. They think it may have happened near the end of the testing but they admit that don't know -- it's wishful thinking than anything else.

Moreover, there was significant damage to the piston crowns, which they speculate to have happened during high loads and high temperatures.

I also don't understand why 0W-16 shows more wear than 5w-30 in the cold engine.

I think what we may be seeing is that the piston keeps getting damaged during the stress testing and when they change the oil to a thinner oil, we see a new break-in because of new minimum oil-film thickness. Therefore, perhaps it would be better to do the test in two separate engines for the two different oils, where this constant break-in effect is ruled out.

 

[PimTac]

I'm not a mechanic but the ring damage looked more serious than "just shedding". There was a small chunk gone along with a bit of the crown as Gokhan mentioned. I'm sure the land was also damage and a cylinder scuff or scar was present. I just tried to find that study and those pictures without success.

 

[Gokhan]

Originally Posted by PimTac
I'm not a mechanic but the ring damage looked more serious than "just shedding". There was a small chunk gone along with a bit of the crown as Gokhan mentioned. I'm sure the land was also damage and a cylinder scuff or scar was present. I just tried to find that study and those pictures without success.

Turbo gasoline direct injection (TGDI) engine-wear test development (January 2018)

 

[Gokhan]

Given the fact that piston-crown damage occurred, it's hard to draw much conclusion from these results. There was ring damage on top of that, too. Would I make anything from my UOA if I knew there was some component failure inside the engine? No.

There is a list in the appendix, showing the order of the tests. Interestingly, the four tests (turbo transient, transient speed -- high load, start - stop, and WOT 3500 RPM) in which 0W-16 did considerably worse than 5w-30 all were carried out toward the end, probably when the piston and ring damages occurred. Also, 0W-16 was always the second oil to be tested. To me it looks like 0W-16 served as a break-in oil when the piston and ring damages occurred, with the increased wear numbers resulting from rebreak-in when the damages occurred. Also, the ring face was comparable between the two oils or 0w-16 did better. I don't really know what to make out of ring side wear (top and bottom sides of the ring). The ring groove was damaged because of the broken piece of the chromium insert and probably it played a big factor in the ring side wear. In any case, these results are inconclusive. That's why using two different engines to test the two different oils would have been much more convincing. There were threads on BITOG asking about what happens to the engine when you keep changing the oil back and forth between thin and thick or different oil types.

This is my take on this latest study on thin vs. thick. It's always a mistrial with a hung jury and a final verdict may never come. Nevertheless, it seems to show that some people's fear of thin oils is unjustified.

 

[ZeeOSix]

Originally Posted by PimTac
I'm not a mechanic but the ring damage looked more serious than "just shedding". There was a small chunk gone along with a bit of the crown as Gokhan mentioned. I'm sure the land was also damage and a cylinder scuff or scar was present. I just tried to find that study and those pictures without success.


They made it sound like there was no associated scaring on the cylinder wall where the damaged ring was, and no spike in wear monitoring (quote: "... no radiation wear data was accumulated related to this event."). I posted the quote earlier in this thread.

https://www.bobistheoilguy.com/foru...re-educate-me-on-0w40-please#Post5002542

 

[ZeeOSix]

Originally Posted by Gokhan
Given the fact that piston-crown damage occurred, it's hard to draw much conclusion from these results. There was ring damage on top of that, too. Would I make anything from my UOA if I knew there was some component failure inside the engine? No.


They made is sound like they didn't see any spike in wear metal monitoring, so they didn't think it made any increase in wear. Word search the PDF to find this stuff.

And as far as the intercooler leak, they said it leaked after the testing was completed.

"Between the end of the test program and disassembly of the engine, the intercooler leaked fluid from the chiller (alcohol-water mix) into the engine."

 

[wemay]

Interesting read, thanks. I'm assuming "start stop" isn't referring to start-stop technology but normal driving stopping and starting. The contrasting wear rate under this condition is pretty drastic, albeit without the use of an oil filter.

 

[PimTac]

On pages 79 and 80 they show the pics and discuss the damage. 5-6mm of chrome insert (?) broke off. There was some cylinder bore damage at the top.

Mentioned also is that all four pistons exhibited crown damage. Maybe Ford needs to evaluate their piston manufacturing?

As I said previously, this was a good test to do however the damage puts a cloud on the results considering that no oil filter was used.

 

[Gokhan]

Originally Posted by ZeeOSix
They made is sound like they didn't see any spike in wear metal monitoring, so they didn't think it made any increase in wear.

I've written a lot of scientific papers and also refereed (peer-reviewed) many. Authors will say anything to justify their results. It's the job of the referees to criticize and decide whether an article can be published as it is or published at all. This is not even a peer-reviewed article.

If there is obvious ring damage, obvious groove damage, and obvious crown damage, it will affect the results significantly. Speaking of spikes, there are multiple. See, for example, the start - stop cycle in Figure 7. There is a factor of 288 difference between the two oils. Is this really a viscosity effect?

 

[StevieC]

I have driven around for sales calls for well over a million Kilometers (over 600K miles) with multiple hot and cold restarts throughout the day on my vehicles and it hasn't affected their longevity that I can measure in the time I have had the vehicles.

The Santa Fe at 300K miles (535,000km) was the longest I ran a unit and although it suffered from a snapped camshaft it didn't use any oil up until that point and had no other mechanical problems prior. I probably restarted that vehicle at least 6 times a day after the initial start.

I had my dad's 2012 Caravan before he had it and for 2/3'rds of it's life so far was spent restarting it an average of 6-8 times a day and it has over 300K KM on it now and it doesn't use any oil.

I did the same with my Journey and although it was taken out in the accident at 100K KM (60K miles) it was also fine. There are UOA's here showing it had very little wear (on what the UOA can measure) and it too was restarted 6-8 times a day.

I'm not saying hot-restart and cold start wear doesn't happen but I don't think it's a major issue at the rate it happens.

 

[ZeeOSix]

Originally Posted by PimTac
On pages 79 and 80 they show the pics and discuss the damage. 5-6mm of chrome insert (?) broke off. There was some cylinder bore damage at the top.

Mentioned also is that all four pistons exhibited crown damage. Maybe Ford needs to evaluate their piston manufacturing?

As I said previously, this was a good test to do however the damage puts a cloud on the results considering that no oil filter was used.


The report said they used aftermarket pistons ... not stock pistons.

"In order to reduce the chance of engine damage, aftermarket pistons were chosen as they have more material below the second ring and thought to be more robust."


Originally Posted by Gokhan
If there is obvious ring damage, obvious groove damage, and obvious crown damage, it will affect the results significantly. Speaking of spikes, there are multiple.

See, for example, the start - stop cycle in Figure 7. There is a factor of 288 difference between the two oils. Is this really a viscosity effect?


The start-stop data isn't "spikes" ... it's the result of 0W-16 causing more wear in that scenario, as was also showed in 2/3rds of the scenarios.

 

[OilUzer]

What is typical hths of 0Wx16? Is there a api range (e.g. between 1.3 & 1.7) or is there a min (e.g. Not lower than 1.3)

 

[ZeeOSix]

Guys, read how the cylinder liners were irradiated (page 6). As mentioned twice now, the area of the liner where the ring front face had slightly denominated was not irradiated, so even if there was surface damage and increased cylinder liner wear from in that area, it was not measured because it was not radioactive.

Understand that they can only measure wear on the materials that were irradiated. That's why the small layer of chromium that flaked off the face of one top ring is insignificant to the outcome. If anything, it would have decreased measured wear by a miniscule amount because that flaked off layer was radioactive.

And again, no oil filter was used because they needed to measure all irradiated material. If some of it was captured in the oil filter it would have skewed the wear measurements (lower readings). They changed oil quite often throughout the testing sequences, so the oil probably wasn't as contaminated as it seems.

 

[wemay]

I agree, the test appears to me as a layman, to be well thought out and without agenda.

 

[ZeeOSix]

Originally Posted by wemay
I agree, the test appears to me as a layman, to be well thought out and without agenda.


The Southwest Research Institute (SwRI) who did this test is a well known unbiased testing laboratory. If you go to their website it shows all the different testing they can perform.

 

[dlundblad]

Originally Posted by edyvw
Originally Posted by dlundblad
One grey area for me is if 0w40 (or 5w40) is suitable for direct injection. Say a Ford EB..

Other than that, 0w40 is a well rounded oil that covers many bases if you want a one fits all.


99% European cars are recommended for oils such as 0W40 and are DI since long before Ford EB.



One of the reasons for D1G2 was the calcium levels and 0w40's can have higher levels of calcium.

 

[edyvw]

Originally Posted by Gokhan
Originally Posted by ZeeOSix
They made is sound like they didn't see any spike in wear metal monitoring, so they didn't think it made any increase in wear.

I've written a lot of scientific papers and also refereed (peer-reviewed) many. Authors will say anything to justify their results. It's the job of the referees to criticize and decide whether an article can be published as it is or published at all. This is not even a peer-reviewed article.

If there is obvious ring damage, obvious groove damage, and obvious crown damage, it will affect the results significantly. Speaking of spikes, there are multiple. See, for example, the start - stop cycle in Figure 7. There is a factor of 288 difference between the two oils. Is this really a viscosity effect?

I would say there are a lot of people here with scientific background that written papers etc. Since you are bragging about it, let us see. Let's see those papers.

 

[FlyPenFly]

In high school I also wrote a number of scienctific papers on things like how the moon affects the tide, why my volcano project didn't go quite as planned, etc. they were reviewed by my fellow students (peers).