Volatility Measurements of 4 synthetics

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Yep, so far Gold and Green appear to have indentical or nearly identical volatility. But I know from my past tests that oils that were close in the early phases of the tests can end up diverging considerably later on. We shall see!

This scale I use is borrowed from a grumpy guy at my work and I just returned it to him today and I'll have to borrow it again later. I hope he keeps liking me enough to let me do so. Thanks again for sending the Green GC!
 
Okay here is a question that has been festering in my about oil burning losses overlayed with NOAK for years ...

[My engine tends to loose M1, GC faster than lets say Chevron Supreme, etc]

The percent by weight lost in these tests ... do you theorize it is the additive carrier oil or base oil being lost? My baseless assumption would be that the carrier oil (mineral in some cases) may not be as resilient to heat and volatilty compared to more resilient PAO's and Ester bases?

Perhaps a UOA * VOA would answer this question by documenting additive PPM's before an after ... or concentration(t) vs (f)? This again would be a baseless assumption
smile.gif
At least I am trying to think like a Chemist *lol*
 
Thanks tensecondz1 for the compliment!

outrun, oil consumption is a complicated thing because so many factors determine it and volatility is just one of them. I think that the other factors are viscosity, seal swell/shrinkage effects of the oil, polarity of oil (stronger polarity causes oil to seep past seals such as valve seals and "stick" to metal more evenly), and the ring cleanliness the oil provides. There may be others I haven't listed. Of course the engine type/condition, and the operating conditions are factors too but those aren't oil variables.

I'm sure that GC is less volatile than Chevron Supreme so the higher consumption you got with GC must be from one of the other factors. If I had to guess what accounts for that I'd guess it's GC's and M1's effect on your seal dimensions, but I could be wrong. When I used Redline for several oil changes with a 2002 Subaru Impreza RS, it consistently burnt it at twice the rate of Valvoline Synpower and Pennzoil dino oil, and I think it was because of Redline's effect on the seals. I know the Redline has very low volatility so we can rule that factor out. If I were you, I'd try to stick with oils that have the lowest consumption in your engine since burning oil forms ash and varnish in your combustion chambers (no good).

You asked about additive carrier oil vs base oil. In a liquid mixture, the total evaporation rate (volatility) should be the sum of the subcomponent's volatility times their volumetric percentage of the whole. Take Lubromoly 0W-40 as an example, it has 80% PAO and 20% mineral oil additive carrier. Let's assume the PAO is all of same structure and has a NOACK volatility of 5% by itself. And the mineral oil has NOACK volatility of 10%. Then the NOACK volatility of the mixture should be 80%*5 + 20%*10 = 6. So the more volatile component raises the volatility of the mixture but not by much because it's such a small fraction of the whole mixture. Of course as time goes on, the more volatile component is leaving at a faster rate and eventually there is very little of it left so the volatility of the mixture rises. It's like putting gasoline in oil and heating it; the gas will evaporate quickly and eventually it wil be mostly oil left behind.
 
Ok, I'm back and have the final Green GC vs Gold GC results. I measured weights at 2 and 8 hours...I slept through the 4th and 6th hours.

Both oils started with 2.01 grams.
Gold GC: Loss at 2 & 8 hrs: 0.17 & 0.45 grams
That's 8.5% & 22.4%, respectively.

Green GC: Loss at 2 & 8 hrs: 0.19 & 0.50 grams
That's 9.5% & 24.9%, respectively.

SO, Gold GC is slightly less volatile than Green GC. What a surprise to probably all of us! That is very good news since Gold is what is getting pumped out of the Elves' Black Forest factory and their is plenty to be had. They have stayed true to their high standards, despite the change in color.

At 2 hours, the Green was much darker than the Gold. At 8 hours, the Green was still darker, but the difference was not as great as it was at 2 hours. At 8 hours, they both smelled the same...like mild burnt corn. That's interesting because when new they smell very differently. Judging by the crude cup tilting method of measuring relative viscosity, it appeared that both oils had the same viscosity at 8 hours (room temp). And that concludes this story!
 
So GC are :

Gold GC: Loss at 2 & 8 hrs: 0.17 & 0.45 grams
That's 8.5% & 22.4%, respectively.
Green GC: Loss at 2 & 8 hrs: 0.19 & 0.50 grams
That's 9.5% & 24.9%, respectively.

but

1. Lubromoly 5W-40: At 4 & 8 hours: 7.0% & 12.0%
2. Lubromoly 0W-40: At 4 & 8 hours: 8.0% & 14.5%

so it seems we should be buying lubromoly at advanced auto parts instead of GC at autozone.
 
Sort of.
I couldn't control ambient temps since this has to be done outside (it's stinky). So the oil temps weren't identical between tests...they were within a test though. So use the first results I posted (that included Gold GC) to compare directly to Lubromoly. And we know that Green GC is just a little more volatile than Gold GC (by 1% and 2.5% at 2 and 8 hours). So Green GC can be compared indirectly to Lubromoly by accounting for the minor extra percentages.

In other words, don't compare the percentages directly between the 2 brands that you pasted above.

But you are right that those Lubromoly oils are less volatile than both Gold and Green GC. But they are higher viscosity oils so some engines may protest from a power standpoint. And then there is the important factor of wear prevention. The 5W-40 Lubromoly has proven excellent at that in UOAs while the few (or sole) Lubromoly 0W-40 UOA(s) show it might not be as good as the 5W-40 in wear prevention. There isn't enough data to be sure. But the 0W-40 Lubromoly has given my VW 1.8T engine considerably better gas mileage than Gold GC did which isn't something we'd expect given it's higher viscosity. My engine consumed a little of the GC while all but one of the 40 weight synthetics I've used don't get consumed (noticably) in 5k miles. So there are many decisions that should go into whether someone should switch from GC to one of the Lubromoly oils. Next run I'm going to use the 5W-40 Lubromoly and see if gas milegage drops. My fiance has a Infinity G35 and it gets Gold GC and I'm hesitant to try a 40 weight oil in it but maybe I will.
 
i have a g35 and i run a 40wt in it. right now its a 10w40 but i'll be changing to either GC gold or perhaps this lubromoly 5w-40. I see no reason to hesitate. for you fiance, just check the levels regulary as there has been a bit of a history of oil consumption with this engine (vq35). Some have as much as a 1 quart every 1K miles. My friends is consuming 1K every 5K which is fair i guess. right now i'm still at zero consumption (measurable that is).
 
Thanks for the G35 info. So far, our G35 doesn't have any measurable oil consumption with GC Gold or the dino oil that was in it when she bought it. We must have gotten lucky! I'm sure whichever oil choice you make (GC or Lubromoly 5W-40), your engine will love it, particularly in the warm deep south where you are.
 
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