Title says it all- why does Amsoil tend to thicken up over time more so than other synthetics?
So why does Amsoil tend to thicken up?
- Thread starter Dude-Man
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I am not an expert. But other synthetics shear due to heat and use. Amsoil does not shear and it oxidizes over time. That is my best guess. What Amsoil product are you referring to? I think with it's newer formulation it is less likely to thicken?
I don't think that it does thicken at a faster rate. However you do see more very long used oil analysis with Amsoil and hence you see more normal thickening due to evaporation and oxidation.
The "thickening out of grade" issue was primarily based on how the Amsoil 5w30/10w-30 used to be formulated. That is to say they had viscosities in the 11.5-12.0 Cst range to start with. In other words, they were borderline 30wt/40wt oils right out of the bottle. So they only had to thicken by about 5%-8% and technically they'd be 40wts.
Now that the Amsoil 0w-30/5w30/10w-30 are formulated at a mid-range 10.5 centistokes, I think you'll see they stay in grade very well, even for fairly long used oil analysis.
Just a reminder, the acceptable range for SAE Xw-30 oils is from 9.3-12.5 Cst @ 100C.
TS
The "thickening out of grade" issue was primarily based on how the Amsoil 5w30/10w-30 used to be formulated. That is to say they had viscosities in the 11.5-12.0 Cst range to start with. In other words, they were borderline 30wt/40wt oils right out of the bottle. So they only had to thicken by about 5%-8% and technically they'd be 40wts.
Now that the Amsoil 0w-30/5w30/10w-30 are formulated at a mid-range 10.5 centistokes, I think you'll see they stay in grade very well, even for fairly long used oil analysis.
Just a reminder, the acceptable range for SAE Xw-30 oils is from 9.3-12.5 Cst @ 100C.
TS
In the Amsoil line, the old formulations of 0w-30/5w30/10w-30 did have a tendency to cruise into SAE 40wt as mentioned by the others.
I used to think this was somewhat by design - and interestingly enough did not cause a spike in wear in UOA showing the viscosity increase. It used to really bug me when (largely untrained) people would insinuate or imply the engine was full of sludge when the oil became essentially a 40wt - maybe this was caused by the mental image of the word "thickening". (Especially funny when the oil went from, say, 12cSt to 13 cSt!). I think we all know sludge viscosity is not 13cSt!!
As to the "why" - changes to VII via usage breakdown and maybe subsequent minor controlled polymerization , oxidation and to a lesser extent evaporation.
The "new" formulations don't seem to have this same viscosity increase with use and as Ted states also start with a lower viscosity.
I used to think this was somewhat by design - and interestingly enough did not cause a spike in wear in UOA showing the viscosity increase. It used to really bug me when (largely untrained) people would insinuate or imply the engine was full of sludge when the oil became essentially a 40wt - maybe this was caused by the mental image of the word "thickening". (Especially funny when the oil went from, say, 12cSt to 13 cSt!). I think we all know sludge viscosity is not 13cSt!!
As to the "why" - changes to VII via usage breakdown and maybe subsequent minor controlled polymerization , oxidation and to a lesser extent evaporation.
The "new" formulations don't seem to have this same viscosity increase with use and as Ted states also start with a lower viscosity.
This jives with the ASTM D-5800 12% Volatility found with the old ATM formula, assuming they're were similar.
Actually I think the evaporation was mainly an issue with the old Series 2000, 0w-30. The reason I say that is that I've looked at used oil analysis with low solids levels that thickened considerably. So I don't think that oxidation is/was the main issue with that formulation. This may also be why the old Amsoil 0w30 seemed to respond well to periodic additions of LC20, since that replaces the most volatile components in the basestock that burn off....
TS
TS
If you look at the 3MP study, for the first 10K miles, the M1 thickened a maximum of about 4%, the Amsoil 8%. Really not too much of a difference. But as TooSlick mentioned, the old Amsoil formula was thicker to start with, so that 8% easily put it into 40 wt territory.
http://neptune.spacebears.com/cars/stories/amsoil.html
http://neptune.spacebears.com/cars/stories/amsoil.html
That may be true...I just happen to remember that Terry had the previous ATM formula measured using ASTM D-5800 and found 12% Volatility. So given a 8% increase in viscosity at 10,000 miles, I don't think oxidative stability was it's issue either.
Miltellas, I think you just ruined my zen like nirvana of discussing Amsoil intelligently without all the hype or antagonism.
Darn darkside Amsoil junkies...
Great discussion btw
Good luck, Miltellas. Sounds like you have a great business opportunity in hand. I wish you the best.
In my 6.9 Diesel, the analysis ALWAY'S came back a 40wt. I to think this was by design in the Diesel Oil. Thought of it as a PERFECT Year round formula. Change oil in late Fall..running thru the Winter at 30wt....here comes the Summer and running at a 40wt...time to change the oil...the leaves are falling out of the trees.
I thought that soot-loading was a major cause of thickening. Although, this is generally referenced in regard to diesels.
"Amsoil Sith Lord" is just a tropology. I wanted to be a dealer so much but... Unfortunately, AMSOIL did not move it's multilevel marketing from USA in Europe. Anyway, I am still the No1 fan of AMSOIL in Greece as before and I love it even that way.quote:
Originally posted by 427Z06:
Good luck, Miltellas. Sounds like you have a great business opportunity in hand. I wish you the best.
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