Results from 6 UOA in 2 years

Thought I'd share some info and ask a question or two. Just got back my 6th Speediagnostix UOA on my 2003 4s. First 2 were using Mobil 1 0W-40 (aka liquid death) and last 4 with Driven 5W-40. Tests were all done at approximately 5,000 intervals and some significant changes are seen after the switch in oils as shown below: Total Wear Metals dropped from 29-22-18-15-9-9, with Iron (valvetrain/cylinder bore) in particular going 13-11-7-4-2-3 Molybdenum ppm when up from 84-78-470-597-517-459 Calcium ppm decreased from 3222-3086-2336-1700-1534-1447 Viscosity improved significantly from 11.7-11.8-13.2-13.1-13.5-13.2 Other items in the reports were fairly consistent across all 6 tests though Boron ppm levels are significantly higher with the Mobil 1 samples (204 & 241) vs DT-40 (152/94/94/96) My one cause for concern is "fuel dilution". here are my numbers: 8/15/19 1.43 2/20/20 1.42 7/3/20 1.10 9/24/20 1.87 10/30/20 1.68 3/8/21 2.52 My car burns almost zero oil, maybe 1/2 qt per oil change. Are these fuel dilution numbers concerning? new injectors called for? Thanks for any feedback

Is there any commentary with the reports that indicate the fuel dilution is an issue, or does anyone have a number that they suggest is a cause for concern? Waiting for my first results. I just changed my injectors, so I don't have any before/after results to work with.

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Yes, this latest report has the 2.52 fuel dilution number coded yellow, meaning "borderline value" vs red (outside normal range) or green (within normal range). FYI, if you are waiting on your first results, unless anything is really out of whack, don't expect to get much operational information. The experts have said its the trends over several reports than are a better indication of engine health vs one static report.

This report would be a combination of time with both before and after with the injectors. On the other hand, I'm hoping to see what it says about other things, looking at issues of bore scoring and IMSB condition and will repeat the test again next spring or earlier if I change the oil before that. I also made the switch to DT40.

I'm planning to replace injectors soon and with this 2 yr history of UOA I will be curious to see if the fuel dilution changes dramatically afterwards.

I can't say it way a lot of fun to change the injectors with the motor in, but I did yet lack the results to show whether it made any difference with the fuel dilution. I just got the impression from reading that it might be a good maintenance item to do that I could likely accomplish myself. Looking forward to the test results anyway.

Nice side-by-side numerical evidence shown. Numbers aside though, I can easily detect enhanced driveability and performance when I switched from Mobil none to DT 40 with a magnetic drain plug.

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Injector replacement, not cleaning, has been recommended by the experts. You made the right move, period!

Post the reports.. The things you posted are missing the main things that I look at when judging UOA.

Most recent UOA Previous 5 tests

Note the large reduction in Zn in the most re cent test, Zn retention is something I watch closely to determine potential mechanical wear that's not indicated by wear metals.. Something is sucking up the anti- wear package.. Likely the fuel dilution isn't helping, but it hasn't hurt the viscosity (it usually does). I'd shorten the next service interval and see what happens.

I am interested in learning how to better understand test results and what the numbers mean, so have a few questions maybe Jake or someone can answer. Looking at the posted results, the viscosity and oxidation numbers are marked with yellow, green and red, but with oxidation it doesn’t seem to relate to high numbers or low numbers? 42.1 in last test gets green as did 43.2 in prior test, but 42.9 in Sept and 42.7 in July got red? I’m assuming these number indicate change interval could be shorter, but the oxidation numbers don’t seem to line up? Do different brands of oils have different limits in this area?

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Lake Speed Jr. and I offered a UOA class last year, we may do it again. In this class we went over how to comprehend these results well beyond the wear metals. Wear metals are generally the least of my concern with UOA. Yes, the oxidation level shows a shorter service interval is needed for this engine. Coupled to the reduction in anti- wear package I�d say that Interval should be reduced to 4k miles at max and see what the results may be. How long will it take you to get 4k miles on this engine?

�How long will it take you to get 4k miles on this engine?� Not too long, already approaching 1k miles in 2 weeks since most recent report date (3/8/21). Guessing another 60 days, 90 at most, and I will be approaching 4k miles on this DT-40 fill. Already have more DT-40 and another speediagnostix sample kit ready to go.

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In that case we don�t have to worry the time playing into the oxidation. Go 4k and sample.

I wonder why Lake Speed doesn't include Nickel as one of the wear metals. IF it wern't for Nickel content on the UOA in this Lab test I couldn't use it to back up analysis of the failed carrier bearings in the GT Mustang . I did an Expert Witness Inspection/Analysis on this one couple of weeks ago.

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I messaged Lake and he said this: "We test for many other elements, including Nickel. The general reports do not include the materials that are not normally found in a particular engine. With this sample no Nickel was present, therefore we reported the items that did show wear metals"

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Well that's an interesting answer since Nickel is very common in most metals and especially in M96 Nikasil cylinders, and since the report has Titanium, Chromium, and Manganese at 0 ppm, but doesn't list Nickel at 0 ppm ? I would prefer a Lab test to list all elements tested for whether there were particles found or not, even if the ppm is 0, it still means something...I wonder what other elements SpeedDiagnostics tests for..

Interesting info OP and thanks for posting. I had posted about fuel dilution recently as well but didn�t receive any responses. https://rennlist.com/forums/996-foru...on-limits.html

I attended The Knowledge Gruppe‘s UOA class back in April of 2019. When they offer it again, I suggest everyone take it. I learned a bunch!

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Thanks Jake! I�ll keep an eye out for the class. Interesting that the higher and lowest numbers are green but between them is a warning. Must be a very narrow band of acceptable oxidation.

Oma1, Oma2 (used monitor analyst 1 & 2, tribologist, STLE CLS previous oil formulator, etc , etc, here. I used to do this for a living. On a lot of engines there are changes that happen when you switch oil particularly if you have been using a certain brand of oil with a determined chemistry and then you switch to some other oil that has a different additive package. All additives that are afine to metal form microscopic layers. When you start up and there is no lubrication what wears is the reactive layer until you get full fluid film lubrication. When you switch oils at a microscopic level what happens the old chemical layer is being removed while the new layer is being established. Also since you switched mentally you are looking for changes and maybe noticed things that you did not saw or looked at paid attention to before. I would get oils all the time at the beginning of us obtaining new customers, my oil pressure drop, the engine is burning more oil etc, etc.one thing to bear in mind, not all oils have the same level of detergent. When you switch at you get a better detergency engine oil deposits are going to be removed, not as fast or drastic as engine flush which I don�t recommend. We developed the following procedure. This is for gasoline engine only. 1. First stage use a Diesel engine oil, Jake recommended Valvoline Premium blue 15w40. I would run this engine oil for 20 percent of the interval. Let�s say you would change at 1,000 miles. You do this because deposits are going to be removed, you don�t want a clogged up oil filter. Gentle clean. Then oil drain and go to your new oil. 1. You are going to used the oil for 33 percent of the interval in this case 1,667 miles. Then second oil change with your new chosen oil at 66 percent of the interval in this case 3,333 miles. Then third oil change with your chosen oil at the original 5,000 miles. Thru all of this use oil analysis. If you wanted to extend engine oil intervals. At this last oil sample is where you start to consider this. I did this procedure with a bunch of taxi fleets, police fleets, and also similar stuff with Diesel engine truck fleets . Listen 70 percent of the wear happens at startup and low rpm conditions. At cold start I want a fast flowing oil. The viscosity issues that you see between the two oils are due to the different formulation. The Mobil one oil has more polymers because it�s a 0w oil than the DT 40. Depending on how you drive (always at high rpms) you are going to shear the pol�mer and loose some viscosity, also you are going to reduced viscosity by fuel dilution. My rule of thumb, as long as the oil stays in grade, example viscosity at 100 degrees c, the oil is good. As long as your oil pressure light does not come up you are good, you want flow not high oil pressure. The higher the oil pressure the highest internal friction, guess what less horsepower, less fuel economy. I don�t know all that Jake and probably lake know about these engines, I know about lubrication and wear. I even wrote the logic for a worldwide program for Diesel engines that would tell you using which oil, with which engine, with with duty type of operation , with which amount of idle time and which quality fuel, also with which level of oil consumption. Will tell you the optimum oil changing interval. No this wasn�t BS, this was based on millions of miles and engine tear downs. Yes by the way I used to work for Valvoline,

Very interesting analysis and recommendations. "Depending on how you drive (always at high rpms) you are going to shear the pol�mer and loose some viscosity, also you are going to reduced viscosity by fuel dilution. My rule of thumb, as long as the oil stays in grade, example viscosity at 100 degrees c, the oil is good. As long as your oil pressure light does not come up you are good, you want flow not high oil pressure" . I do tend to drive at high rpms after warmed up, love hearing the factory sports exhaust, and will usually get in at least one solid high rpm run through the gears per heat cycle. Never seen my oil pressure light other than when my sender unit was failing and would send faulty 0 reading for a few seconds before returning to normal. That's been repaired.

I am learning more about these engines as I go, something that I have seen is that some people buy some of these cars since they are affordable and then most off then were not properly maintained and then you get all kind of issues. You see cars that were maintained at the local joe blow oil change, good knows what oil they put in them. I spoke with a fellow tribolist at Mobil. Third level Tech support. I had to identify myself at the second and third level. He disclosed some more specs about the formulation of 0W40. Anyway I was interested in Antiwear zinc and phosphorus level, and also in TBN. He stated to me that typical TBN 12.56. Anyway that level of TBN is really similar to amsoil and they tell you real long drain. TBN is an indication of detergency and dispersancy. detergents clean, dispersants keep the contaminants separated suspended almost like encapsulating something, so they dont conglomerate and become larger particles. I noticed some missing items that I would love to see in the oil analyses. One is TBN, the other is VI, yes I know only a few labs do used oil VI. Another interesting thing on this oil analysis is that the analysis indicates remaining life and to be honest I am skeptical about that. I would be really interested in knowing how they are measuring this. In a vehicle the car computer has engine hours (can calculate Iddle Time), also you can know long, short trips, fuel consumption, all kinds of info that an oil lab looking at an oil anaIysis would not know. I would like to like to see TBN and TAN numbers in the lab report. Anyway It will be really interesting to know TBN level on new Driven. Also please dont interpret higher TBN as Better what you need to see is how fast is the TBN depleting. Since out of 40 maintenance records on my car it was serviced at Porsche dealerships, only one at a Honda place for an oil change. I am sticking with Mobil 1. Yes I got original block, not sure if engine was ever rebuilt, but I got a 3.4 L. One last thought a clean engine is an efficient engine both in terms of power and fuel. I really worked on Fuel economy with a bunch of fleets all over the world, guess what on fleets that had at least 100 trucks (big Rigs) almost 40 percent of operational cost is fuel.