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One correction: I mixed up the iron and aluminum labels in my table above! Should be this:
Originally Posted by Petza914
The problem with this analysis is that viscosity breakdown and metal wear aren't linear functions. It doesn't work out at the 6 ppm of alumimum metal wear over 5,000 miles would be 3 ppm at 2,500 miles and the same issue with viscosity breakdown. And the 2 are also related in that once the oil shears to a lesser grade the metal wear numbers increase which is one reason why you do UOA to determine what that change interval should be. This is exactly the reason the mileage interval was shortened on my car from the earlier runs of 5,500 miles then 4,000 miles, etc in order to get the viscosity numbers where they need to be to protect the moving parts. Viscosity matters because of film strength that separates the moving parts. If your 5w40 is shearing to a 0w20 in 3,000 miles then it's no longer doing it's job or meeting the spec that the manufacturer called for and that M1 sample was barely in the blackstone range at that 5,500 mile change interval and with the double digit iron wear, wasn't working anymore.
No, you're thinking about that backwards.
You're absolutely right that metal wear may not be linear. In fact, it probably does trend upwards as the miles on the oil go up. But if we assume that's true and we apply that to your Blackstone numbers, it makes the M1 look better, not worse, because the M1 did more miles than the other oils.
Let's do the math: over 5500 miles the M1 averaged 1.8E-3 ppm/mile for iron. (I'm gonna leave the exponent off from this point forward and just say "1.8"). We'll call the initial wear rate "w". Assume you're right, and say at 4000 miles the M1 suddenly wore out and the wear rate doubled (so 2*w). We know the average iron wear rate is 1.8 over 5500 miles, so we get this:
1.8 = (4000*w+1500*(2*w)) / 5500
You're producing wear metals at rate w for 4000 miles and then 2w for 1500 miles. You add those and you get the total wear metals, and then you divide that by the 5500 miles total to get the average rate (which we already know from Blackstone is 1.8). Doing the math, w = 1.4. So for the first 4000 miles the M1 iron wear rate was 1.4, and then it went up to 2.8 (1.4 * 2) for the remaining 1500 miles.
You see what that means? If we assume the oil performance gets worse over time, then if you'd changed the Mobil 1 at 4000 miles (like you did for the Driven) the M1 wear rate in the table above would've only been 1.4 versus the 1.7 avg. for the Driven. So the argument you're making is wrong: if the Mobil 1 protection had really degraded as the mileage went up, then the data show it performed better than the Driven over an equivalent 4000 mile OCI. This is how that would look if you plot it out vs. what you'd get in the Blackstone report:
Now, do I think that really happened to any extent over your tests? Probably not: I'd assume wear was actually reasonably linear. But the exercise shows that the way your'e thinking about this is wrong.
As for viscosity, go back and read what I wrote in my prior post: how do you know the viscosity is "too low"? We only care about viscosity to the extent that we want it to be in the range to minimize metal wear. So the UOA interpretation should based on the wear numbers: if the wear numbers are good then the oil is protecting fine. If the wear numbers are *bad*, well, then you look for something else in the numbers that could be causing it...like, sure, low viscosity. But your M1 wear numbers adjusted for mileage don't look significantly different from the other oils you used, so the "low" M1 viscosity is not a problem.
"But it fell out of the 40 wt range"...so what? The lower bound of the 40 wt spec is not some magical number below which the oil no longer protects. Also the M1 final viscosity is only 7% lower than the average Driven value: not exactly a huge difference there. But even if it were, who cares if the wear values are good? the M1 wear numbers look fine, so it was still protecting perfectly well despite being thinner.
Anyway, your data set are too small, noisy, and uncontrolled to draw any strong conclusions about "better" or "worse" oil brands. All you can say is that all three oils performed well, there are no significant differences between them in terms of wear, and Mobil 1 0W-40 in your car is good out to at minimum 5500 miles. Anything more than that is playing in the noise and wishful thinking.
tldr: Just use any A40 oil you feel good about and change it at some sort of reasonable interval
It's hard to draw real conclusions from the 997 report because mileages are different and 3 different oils are used.
Here's my Cayenne history where the use interval is more consistent. Car had been serviced at 25,000iles at the dealership including an oil change with M1 Ow40 European Formula. All the other changes are Driven DT40 and with the newer high Moly version the entire time
See how the metal wear numbers went down as I flushed more M1 from the engine and then stabilized at very low numbers also with higher viscosity.
Hard to argue with what's shown here where even with 50-100% more miles per interval than the M1 was ran for the wear is much lower, especially as I got all the M1 oil out of the engine by the 3rd oil change.
You have no idea how many miles are on that original M1 change, so you cannot make any comparisons based on that. And with data that bounce around this much it's easy to cherry pick to come to the conclusion you want. Like, your aluminum went up 20% in the last change, so Driven sucks? And it doesn't take four oil changes to "flush out the M1", lol, it's not like it's acid in there sitting around doing damage. And if flushing out the M1 made the Fe numbers better, why did Al go from 4->2 on the first Driven change but then went up to 4-5 as you used Driven more? All the numbers are so low anyway, are any of the changes you're seeing even significant? Playing. In. The. Noise.
(Also you keep referring to copper as bearing wear. That seems pretty unlikely given that the copper in the bearings is under steel: if the copper is exposed on the bearings you're pretty f-ed. More likely it's dissolved copper from yellow metal somewhere else in the engine (higher TBN is mildly corrosive for that) like the oil cooler or something, but who knows? So I really doubt that's telling you anything unless it spikes)
Look, your car runs fine on Driven, use it if you like it. And I don't think you're getting anything useful out of ongoing UOAs, but knock yourself the heck out if you want to do them. But I (and many others) don't think UOA data are useful for what you're trying to use them for, and I definitely don't think they show that M1 0W-40 is bad for these cars, so you guys gotta stop with the "M1 is automotive abuse use, magic brand XXX" crap.
You have no idea how many miles are on that original M1 change, so you cannot make any comparisons based on that. And with data that bounce around this much it's easy to cherry pick to come to the conclusion you want. Like, your aluminum went up 20% in the last change, so Driven sucks? And it doesn't take four oil changes to "flush out the M1", lol, it's not like it's acid in there sitting around doing damage. And if flushing out the M1 made the Fe numbers better, why did Al go from 4->2 on the first Driven change but then went up to 4-5 as you used Driven more? All the numbers are so low anyway, are any of the changes you're seeing even significant? Playing. In. The. Noise.
(Also you keep referring to copper as bearing wear. That seems pretty unlikely given that the copper in the bearings is under steel: if the copper is exposed on the bearings you're pretty f-ed. More likely it's dissolved copper from yellow metal somewhere else in the engine (higher TBN is mildly corrosive for that) like the oil cooler or something, but who knows? So I really doubt that's telling you anything unless it spikes)
Look, your car runs fine on Driven, use it if you like it. And I don't think you're getting anything useful out of ongoing UOAs, but knock yourself the heck out if you want to do them. But I (and many others) don't think UOA data are useful for what you're trying to use them for, and I definitely don't think they show that M1 0W-40 is bad for these cars, so you guys gotta stop with the "M1 is automotive abuse use, magic brand XXX" crap.
Maybe you missed the part where I said the Cayenne had been dealer serviced at 25,000 miles with an oil change, so I do know how many miles were on that sample - it was 3,425 and dealers use Mobil 1. It also doesn't show that it took 4 changes - it took 2 - the original change and then 1 more. That's when the iron and copper wear went down 50% and then stayed there for the next 10k miles.
Is M! as bad a SuperTech from Wal-Mart - probably not.. Is it as good a Driven or LM Molygen (green jug not the other ones as they also show high Iron & copper and lead) - nope - it shows higher metal wear and lower visocisty in fewer miles. Look up the oil anaylsis thread that has over 40 UOA reports in the spreadsheet all from 997s. With a sample size that large and consistent results from different brands, reasonable conclusions can be made.
I was reading an article about a decade ago in Turbo Diesel Register in regards to oil quality. The author was a former
additive specialist at Lubrizol. They provided additives for most oil companies. The only oil he really found fault with was
Exxon Mobil. Apparently it's know in the industry as the XXX oil, as they skimp on additives. Porsche must get it really cheap.
I doubt very much Porsche uses it in their race cars.
I was reading an article about a decade ago in Turbo Diesel Register in regards to oil quality. The author was a former
additive specialist at Lubrizol. They provided additives for most oil companies. The only oil he really found fault with was
Exxon Mobil. Apparently it's know in the industry as the XXX oil, as they skimp on additives. Porsche must get it really cheap.
I doubt very much Porsche uses it in their race cars.
What no one knows, is how Porsche came up with their A40 formulation. While some think it is a Mobil-Porsche conspiracy, the A40 spec is available from many oil makers. I just find it hard to believe Porsche would compromise their product for something like oil. Porsche like all car makers have many masters including environmental laws, USA's COLA and similar regulations in the EU, India, Japan, and China (yes they do and they are tough... they are promoting an electric car future). Throw in environmental laws across the world.... Sheesh!!! I have real trouble believing Porsche has enough freedom to dick with an oil formulation.
Peace
Bruce in Philly (now Atlanta)
Last edited by Bruce In Philly; 04-21-2024 at 08:09 PM.
No manufacturer can afford to dick with an oil formulation. Not just Porsche. It seems we're getting into conspiracy theories about Mobil and its oil now. Ridonkulous. BTW, I am not a Mobil fanboy. I always use Motul.
Originally Posted by Bruce In Philly
I have real trouble believing Porsche has enough freedom to dick with an oil formulation.
Yeah that's my point. Mobil isn't significantly any worse or better than any other approved oil for our 997s. Pick your flavor of ice cream and enjoy. I just don't see the need to debate or belittle anyone's choice of oil. This thread is like many other oil threads: beating a dead horse.
Originally Posted by MrMoose
If it's a conspiracy it's a REALLY BIG conspiracy, lol.
What no one knows, is how Porsche came up with their A40 formulation. While some think it is a Mobil-Porsche conspiracy, the A40 spec is available from many oil makers. I just find it hard to believe Porsche would compromise their product for something like oil. Porsche like all car makers have many masters including environmental laws, USA's COLA and similar regulations in the EU, India, Japan, and China (yes they do and they are tough... they are promoting an electric car future). Throw in environmental laws across the world.... Sheesh!!! I have real trouble believing Porsche has enough freedom to dick with an oil formulation.
Peace
Bruce in Philly (now Atlanta)
What I was referring to in the video is the matter of Mobil 0W40 barely meeting the "40" spec. As the video points out, usually
when this used oil is tested, it is sheared to a 30. It's not holding up as a 40 weight oil. Again, not enough or poor additive package.
Blame the gov't or what ever. I wouldn't use it.
Better.... what is better? I have no doubt there are better oils to put into our cars... butt... oh that big butt... is it necessary? Anywho... I will continue to use Liqui Moly oil with Ceratec additive. Why? I dunno, it entertains me. I FEEL better. I have a cognitive dissonance in my head... all those voices again... intellectually, I have no issues following a maker's recommendation... emotionally, I want to do better. I keep my cars a long long time. If my 2000 Boxster S didn't blow two engines, I would still be driving it today assuming the wheels didn't fly off of it by now. I am also scarred by history... my father buying so much GM crap in the 70s and 80s... me buying GM crap back then... So my emotions kick in, and I hate to admit it, I worry about my car blowing up again. If my 2009 C2S so much as farts, I freak out... So....
Peace
Bruce in Philly (now Atlanta)
Last edited by Bruce In Philly; 04-22-2024 at 09:08 AM.
I think where I have got to with oil choice is, I will actually move from Mobile 1 to another brand and probably LIQUI MOLY or Millers etc. Only because Mobile 1 has a higher level of detergents (specifically for longer mileage use which I dont need) some choices in additives to reduce the risk of LSPI, perhaps with the 0w40 variant. I do like the idea of upping the top limit to add a minor amount of viscosity for track days and hard driving, this is worth watching, nothing new but fair comments and interesting to see that race oils do have similar additives
The horse is always killed by the same conclusion. Use what makes you sleep at night. Any AP40 will do for wear. No oil will prevent/heal a defect like scoring or low speed bearing issues.
I blame STP, Slick 50, Marveles, Seafoam, etc. Its almost like FOMO.
04-17-2024, 08:48 PM
