Originally Posted By: OVERKILL
Originally Posted By: Nederlander75
Originally Posted By: OVERKILL
Originally Posted By: Nederlander75
I few years back Buster posted commentary from Mobil regarding UOAs with them saying outright that metals in UOA were indicative of engine wear. This was presented by him at that time regarding the higher FE levels in M1 UOAs.
I believe this was the other way around. Mobil stated that engine wear could not be gleaned from a UOA. I also believe buster posted about an F1 team that used UOA's with their custom blended lubricant, but again, this was on a specialized piece of machinery with highly controlled conditions and materials as well as massive trending in place. Definitely not relatable to firing off a UOA to Blackstone.
See post 1557975 in the "What is the iron issue with Mobil 1" thread. In lieu of the warm fuzzy speculation going on here this plus the Blackstone comments seem to provide concise evidence in favor of conventional oil. Of course resources and time permitting a tear down or other high $ observations may refute or support these conclusions, but for us average users UOAs are the best method for determining oil use including wear mitigation.
I prefer the quote from Redline in that thread that buster posted:
Post from Redline on UOA's
Originally Posted By: Roy from Redline
Unfortunately, oil analysis is not very good at distinguishing wear between different formulations. Emission spectroscopy has a particle size limit of 3 to 5 microns, which means that particles larger will not be detected. Unfortunately, most serious wear issues generate wear particles in the range of 5 - 15 microns. Oil analysis only measures about 15-20% of the particles in the oil, and changing form one formulation to another is likely to change the particle size profile. Usually formulations with more antiwear additive will more aggressively react with the metal surface and when rubbing occurs will produce smaller particles. Generally, more antiwear additives will give greater iron spectrochemical numbers, even though the total iron can be lower. There are other techniques such as ferrography, which looks at the wear particles under a microscope, but now we are talking about analysis many times more expensive than spectrochemical analysis. The oils with the better spectrochemical numbers will be much less chemically active on the metal surface, so they will be less able to handle more severe loads. There is always a trade-off between chemical wear and adhesive wear. Chemical wear is the very small particles and soluble metals which is identified in the spectrochemical analysis, while adhesive wear is many orders of magnitude greater than the chemical wear, but much is not identified in spectrochemical analysis. But if you were using spectrochemical analysis as a maintenance tool and started seeing a deviation over the baseline, then you would know something was wrong.
It is very difficult for an individual to be able to look at numbers which will conclusively determine the best formulation, you simply have to rely on the reputation of the marketer and whether you trust the marketer's technical expertise. With most of our formulations, we rely on major additive manufacturers to do the basic API sequence testing to determine criteria such as antiwear, dispersancy, cleanliness, etc. All the oil companies rely on the additive manufacturers to do the engine test work. We will take their basic package and add additional antiwear, friction modifiers, oxidation inhibitors or whatever can be safely modified to provide superior performance. Some of the bench tests such as 4-Ball can be useful, but a blind adherance to optimize with one single test will result a less-than-optimum performing lubricant. There are always trade-offs in engine oils, and we try to enhance antiwear and friction reduction at higher temperatures and loads, while trying to maintain performance at lower and normal loads and temperatures.
Regards,
Roy
Which sums up the issues with attempting to use UOA's to compare oils and wear quite aptly.
In contrast, the post you are referencing:
buster's quote
states:
Quote:
ExxonMobil's mobile laboratory will be present at track tests and samples of engine oil will be taken and analysed after each run using a spark emission spectrometer. This measures 19 seperate elements in parts per million, with abnormal readings indicating possible potential problems. For example an abnormally high iron reading may indicate an increase in wear or stress on components in relation to the previous oils tested.
1. This is the race car quote I was talking about.
2. They specifically state ABNORMAL readings yielding POTENTIAL problems. We are not talking about 10ppm difference here and we are talking about using the same lubricant. This is the difference between samples of the same lubricant, in the same service in the same equipment with an established trend of normalized figures and then focusing on ABNORMAL readings; deviations, from those trends. This in no way resembles the use of $20 UOA's on BITOG under widely varying operating conditions using a myriad of lubricants and trying to divine out some holy grail of engine wear by using a tool that was never designed to be used as such.
I participated quite actively in that thread and remember the discussion well.
Ultimately you actually need to tear down the equipment if you want to measure wear. People believe all kinds of spectacular malarky, but that belief doesn't make any of it true. Look at what Roy wrote. Think about what he's saying and the variables in play and then consider how that works to bring in countless unknowns and questions about what is being sampled and the makeup of the products themselves when one attempts to use UOA's to contrast wear rates between different lubricants.
Significant deviations from established trends can bring to light questions about the health of a piece of equipment. These abnormalities are exactly what the quote from XOM's mobile lab is referencing in terms of analyzing lubricants from these race cars. This is the same way the tool is used when sampling genset sumps, OTR trucks, earthmoving equipment, hydraulic equipment....etc. The lubricant is the same and there is an established trend for the equipment. This can save a company tons of money by allowing not only the extended use of the lubricant but also a snapshot into the health of the equipment and the chance that an issue can be mitigated while it is still small and subsequently the prevention of total failure. For example, the sign of coolant in the lubricant pointing to an EGR cooler failure on a truck versus having that engine fail. For an automotive example, a TDI Jetting with a sudden and massive uptick in iron indicating an impending camshaft and/or bucket failure.
Still doesn't change the fact that UOA is the best tool available to the masses and that tool's results lean in favor of conventional. Not saying I'd choose conventional personally just that for the average user it appears to make the most sense given the support for it and lack of widely available evidence to refute its supremacy in the context of the OP.