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Heres the background: Mobil1 15w50 with 1 quart of lucas addidtive. This was the first oil change since a head gasket job that involved heads being outsourced for work (I'd have to check the receipt but I think they did new seals), cam tower gaskets, oil pan gasket.
Some of the wear metals are indicating a bit high. I'm wondering if any of that could have come from the aforementioned work. I'm also guessing that the high silicon may have been due to that work. I'd greatly appreciate any insight!
(Car runs great. Holds about 2.5ish bar at hot idle)
Metals do seem a bit high, but not alarmingly so. Averages for our GT engine, with samples every change (4-6K miles) over 100K miles or so prior to rebuild, show aluminum and iron around 5-6 ppm, copper mostly in the 5-8 range, lead 3-5. That seems pretty consistent with other reports.
The silicon is almost certainly from the sealers that were used, and potassium is likely a bit of coolant that got into the crankcase with the heads off.
What concerns me is that the zinc is less than 800 ppm. I don't think that is adequate for these engines. The Mobil-1 product specs (link) show 1300 for 15w-50, plus the additive, so something is not right here. It's been eight years since I tested Mobil-1, but my sample of used 15w-50 then was 1100 (mileage unknown).
I assume you changed oil with this sample? And put in the same Mobil-1 15w-50?
What I would strongly recommend that you do is send out a sample of the virgin oil you just put in, and see what the zinc level is. If less than 1100 or so, then change it out for something else. Over the 120K miles that we've had our GT, we've used Amsoil, Torco TR-1 and SR-1, and Brad Penn-- all 20w50, all performed well according to the oil tests, and all tested 1000-1400 zinc.
This is really interesting. I've always used Mobil 1 15W-50 for the same reasons. I've never run a UOA and assumed the specs on the Mobil 1 website were correct. Seeing that Zinc level so low is a bit alarming.
It is interesting, but I want to avoid jumping to any conclusions about Mobil1.
This oil had a quart of Lucas in it as an additive. It was also the first oil change after head gasket and other work that was done by a shop. I left the Mobil 1 15W50 with the shop, but did not visually see them add that oil to the car (again, not questioning the shop at all either). There are just more unknowns with this oil change than any other that I've done.
Unfortunately it will be awhile before I can submit a sample of the mobil 1 due to an impending move.
This is a mystery. I did some searching and did not find any indications that Mobil has reduced zinc levels. But I am also not convinced that your sample really was Mobil-1 15w50.
The basic additives are consistent with Mobil-1 but lower amounts: The primary detergent/dispersant was calcium, but Mobil-1 15w50 is 2300-ish while yours was 1874. There should 70-80 moly, yours again was lower as was boron. Zinc, phos are both way low. Viscosity however is right on for a 15w50, but my understanding is that Lucas is basically a viscosity modifier (thickener) with no additives, which would increase viscosity of a thinner oil.
So what this smells like is a thinner Mobil-1 (which would be required to have a lower zinc level), with the Lucas added to bring up the viscosity.
I can't think of anything else that would reduce the zinc level that much: that's basically the level of a GF-5 rated 10w30.
Can you clarify the history a bit? The report shows 2,800 miles on the oil, was that that previous change before the head-gasket work? Or after? Did you do that change, or a shop? Why was the quart of Lucas added?
On the left is a used oil analysis for our GT when we first bought it, 151K miles on the engine and miles-on-oil unknown.
Mobil-1 15w50 but may have been diluted with something else, viscosity and zinc were both a little low.
On the right is a VOA for Mobil-1 15w50 posted to the BITOG forum a few years ago (link):
And, this is why I add the Rislone ZDDP additive in my car. Mobil 1 still does not have enough zinc in it. Even the oil companies have caved to environmental regulations, and the panic that just the slightest increase in PPM of Zinc would destroy a catalytic converter.
This oil analysis now gives buy-in that a ZDDP additive is a good idea.
And, this is why I add the Rislone ZDDP additive in my car.
As it has been posted 1,000 times over, here is one more.
The complete additive package is just as important as specific levels like ZDDP. Just dumping in an additive for ZDDP doesn't guarntee anything. Best to find an oil that meets your needs and yes, they do exist.
Originally Posted by Mongo
Mobil 1 still does not have enough zinc in it.
If the posted numbers by Mobil 1 are true (the PDF from Mobil, not this analysis), then yes it does. The 1100/1200 levels is what oil contained back in the 80's and is all you need today, especially in a bone stock S4.
Originally Posted by Mongo
This oil analysis now gives buy-in that a ZDDP additive is a good idea.
Other oil analysis of Mobil 1 15w-50 have shown the adequate levels of ZDDP.
And, this is why I add the Rislone ZDDP additive in my car. Mobil 1 still does not have enough zinc in it. Even the oil companies have caved to environmental regulations, and the panic that just the slightest increase in PPM of Zinc would destroy a catalytic converter.
This oil analysis now gives buy-in that a ZDDP additive is a good idea.
No, it doesn't, and additives aren't a good idea. If you don't think Mobil-1 has enough of something that you want in your oil, then use some other oil that does. There are lots of choices.
Mobil-1's product data sheet (link) shows 1300 ppm zinc, which is fine. That is also confirmed by all of the VOA's that I have have found on the innerwebz. (Search for: Mobil-1 15w50 VOA).
How would a small bump in ZDDP concentration from Rislone be detrimental to any component of the engine other than than maybe killing the cats sooner? I would also like to add that every single lifter noise has dissipated since using this product. I have left the car parked for 2 months once during a move, fired it up, and still no odd noises anymore.
Here is the tech sheet to the stuff I use. If my PPM is around the 1700-1800 they claim, how is this bad? I am also not using the entire bottle on an oil change, but only 2/3 - 3/4s of it, which would make my concentration less theoretically than what a full bottle would bump ZDDP levels up to.
With regard to the analysis done by the OP, the tech sheet for Mobil 1 15-50 shows more than what is actually in the concentration. Whether that is due to the Lucas additive or not, there needs to be some clarity in why the numbers are less.
Everyone is welcome to opine all they want on this, and Erik I have read through the oil threads and see at least two other RL'ers who are doing the same thing I am doing with zero complaints. I don't believe there is a wrong answer to this unless you're running some oil that is an off-brand with zero info or lack of a fact sheet.
Ok, here's more history. I have done all the work on the car myself up to this head gasket job that I had someone else do. I have never been inside an engine and didn't want to mess around.
I noticed my oil pressure was a little bit low after getting the car back from the shop (dropped to around 1.5 bar at hot idle at one point). I called the shop to confirm that they had used the Mobil 1 15W50 that I had supplied to them and they responded as an affirmative that they had. They recommended adding the lucas to increase oil pressure, so I drained a quart of the oil and added a quart of Lucas. I thought it was suspicious that my oil pressure was low after having them do an oil change (hence the call to confirm that they had used my oil), but seeing how they had also done a pan gasket I thought maybe there had been some disturbance to the oil pressure sender unit.
This oil analysis was done when I drained the oil that was used by this shop. I performed the oil change myself, so I now know for a fact that Mobil 1 15W50 is in the car at this time.
Based on the very insighful comments above, I'm going to assume that the shop ended up not using the oil that I supplied and it was probably a lower viscosity.
This makes more sense, thanks. So the Lucas brought the viscosity back up to where it should be, but not the zinc. That my also explain the wear metals being a little higher than expected, but hopefully no harm done.
If the hot idle oil-pressure is back to its happy 2.5 bar then I wouldn't worry for now, put another few thousand on the car and then check it again.
How would a small bump in ZDDP concentration from Rislone be detrimental to any component of the engine other than than maybe killing the cats sooner?
You and I are not chemists and asking such a question is way over our heads. Everything I've read talks about upsetting the additive package already in the Mobil 1 (or whatever oil).
Think of it this way. You are making cookies and you read that whole wheat flour is good for you, so you dump in triple what the recipe calls for. You end up with horrible cookies.
Probably a stupid example, but hopefully the point gets across.
Bottom line, it may not (and probably will not) hurt anything, but it's not necessary so why take the chance? If the EPA really did strip 50% of ZDDP from all oils and outlawed boutique motor oils, then we would need to roll the dice and start experimenting. That hasn't happened and I doubt it ever will. The vast majority of cars on the road are compliant, they are after the bigger fish and if you kill your CAT with ZDDP oil that is your problem to deal with come emission testing time. The whole thing will eventually go full circle.
02-22-2017, 11:07 PM
First Oil Analysis
