I know we've had a few conversations about oil analysis from different labs on RL and I know valve guide wear is always a concern on our list. Just thought I'd get some feedback about my latest oil analysis results. The only concern at this time, I guess, is the elevated copper levels. Thoughts?

Car History:
Bought with unknown history at 43K. I've taken good care of her since as I do a bit of the service work myself. Done routine oil changes with filters changed every time. I've been driving her very infrequently (maybe 5K a year) and running the usual, crummy 91 Octane California gas in her. Has a few slow oil leaks in the usual spots (chain case, under manifold, maybe a slow leak by cylinder or two, valve cover gaskets replaced and perfectly dry).

She's now at 76K. I had a PPI by Tony Callas at purchase and switched over to Motul for last few oil changes on his recommendation. She only burns average 1 liter per 1,800 miles.

Oil analysis:

 

well typically high copper would make me concerned about bearings, but your low lead would lead me to believe that its not an issue.

If this is your first one, I'd try 5k miles for the next one and see what you got.

 

Looks average with slightly higher copper.
Check this thread, it has a few reports listed.

https://rennlist.com/forums/993-foru...-analysis.html

This is interesting, too
https://rennlist.com/forums/993-foru...per-cores.html

My results are similar to yours with slightly higher copper and much higher iron on 5k-mile M1 15w50 with spirited and track driving on it. My car also has 78k miles and burns about 1qt per 1.5-2k miles.

I wonder how much the results are affected by how the sample is taken and tested and what that even means. Just because everybody changes oil at 3.5k mile intervals resulting in certain particle averages that doesn't mean that higher level is worse and at what point it should be alarming vs normal. Plus there are so many other variables, I'm not really sure how much real value these reports provide except for something to talk/worry about.

 

Why are the viscosities so high??

 

Yes, Quad, that was what I was thinking. Looks like some bearing wear but not significant to show higher copper levels or elevated lead.

I agree there is a bit of guessing with these types of tests. But I also think trends are a lot more revealing than just absolute levels. Also, bronze wear from our softer valve guides would make me think about both elevated copper and lead which is always a concern in our cars.

My same question I was going to post to Blackstone. Besides using higher viscosity oil from the start (which I'm not as I'm using 15W-15) I can't think of what would cause a thicker fluid - maybe carbon waste products?

 

Does the make up oil of 3.35L mean that you used that amount of oil in the 5953 miles on the oil?

 

Yes. Maybe that's why the viscosities are so high. I missed that.

I don't know Motul's products real well. I know they are quality. Is this one a full synthetic or blend?

It's only one report. We really don't know if wear metals are doing up or down.

If it were my car, I'd run Mobil V-Twin 20W50 and change every 5,000 miles.

 

Its a blend. I run it in my car as well and am pretty happy with it!

 

But why would adding more oil make the viscosity HIGHER than normal? I would think that the oil would be cleaner (have a higher TBN, etc.) but not a higher viscosity.

The Motul oil I am using is Motul 6100 Synergie which is a semi-synthetic brand. They do make a fully synthetic but I was even told by some experts that it was not necessary to go this route for a street car. But I do not want to make this conversation about oil type - we've talked so much about this in other posts. I'm just trying to learn more about the analysis of oil and their correlation to engine wear.

Yes, I am very interested in finding out the trend for my oil analysis. Absolute numbers don't always show the whole picture.

 

Probably because the 3.3 liters of make up oil has not sheared down as much. Call Blackstone, they should be able to explain it to you. It's like the difference between a VOA and a UOA.

If you want your wear metals to drop or hold from increasing, start using a quality FULL synthetic oil. Like the V-Twin or the proper Motul. If you want to use a blend, then select Brad Penn.

 

Just spoke to Blackstone about my analysis. They state that adding newer oil to the old, as long as it is same weight and type, should NOT raise the viscosity out of the normal range. However, they did notice that Motul oil tends to have a higher normal range than many oils of 15W-50 type which may explain my high viscosity. Another cause for high viscosity is if oil runs hot. However, that would also result in a higher insoluble number as the oil begins to break down more. A TBN at 5.4 is a very strong number to further support the long health of my oil and support the notion that my oil did NOT run too hot.

I also asked if switching to a fully synthetic would help or change the situation here. They stated that fully synthetics tend to hold their viscosities for longer duration when compared to conventional or blends. However, my oil does not appear to have this problem. So they didn't see the point.

I'm definitely going to repeat the test to see my trends. I'm also wondering if my southern California environment warrants a different weight oil since 15W-50 seems to be the recommendation for all our 993's, regardless of climate. Seems to me that would should adjust for that. Germany has a similar environment to the east coast. For us in Calif, we rarely see the temp drop below 40F in the coldest part of winter. But that would further argue keeping a heavier weight oil then, wouldn't it?

I do notice (placebo possibly) that my engine seems to burn less oil with Motul on startup than my previous Mobile One I was using and engine appears to run smoother - but it's probably all in my head.

Another test would be a fully synthetic Motul vs Joe Gibbs. Without getting into the heated discussion about oil brands here, I attended a tech session at Tony Callas' shop a few months back and their research and results with their race engines from their "driven" products was impressive. His shop seems to have switched over to Joe Gibbs, but Steve Weiner still is an avid fan of Motul 6100 Synergie.

 

Racing vs daily driving is apples to oranges so I'm not sure how much relevance this research has.