Amsoil: How Many Years Could it be Kept in Service

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The Amsoil vs Rotella-T thread got me to wondering. I have crunched the numbers with high dollar synthetics and found that to make them pay on my small farm, I'd have to run them at least 5-6 years in service. I'm running Rotella-T out two years and about 75-80 percent of the rated OCI hours now after great UOAs at over a year in service at about 50 percent of the rated hours. I was intending to test again and maybe try three years.

Amsoil people; what you you think... 5-6 years possible?
 
I just don't know about 5-6 years. Moisture, acid, used up TBN would affect the oil long term. I"m guessing a lot of your equipment is seasonal, and don't get the hours on it.

I would look at other options for using synthetics, hydraulics and transmissions come to mind. Maybe engine oil in your situation wouldn't work.
 
Just thinking out loud here - let's say Jim is using a very stout synthetic w/ very high starting TBN (Rotella T may fit that bill) - how about he gets a fluid extractor, and on certain intervals (based on known abuse rate on oil - via past UOAs) - he pulls 1 or XX qts out thru the dipstick and replaces with the same stout oil. Also chges filter at it's guestimated life span.

Thus, you're pulling out wear metals and other junk, your refreshing the TBN (even if this requires replacing (eg) 25-40% of the oil) - so you should end up with oil in the crankcase well under condemnation limits for TBN, Visc. and wear metals. And then finally dump this at XX number of years.

Would a cost analysis show this to be optimal? And could this method prove legit concerning effective/safe lubricity ?
 
Here is the deal. As long as you service the filters ( full flow and bypass}, a true PAO based synthetic could last indefinitely. You would have to change out the filters on a scheduled basis and replenish the oil as needed.
I have a 2005 Duramax diesel that has not had an oil change in 40k miles. However I change the full flow every year and the bypass filter every other year. I keep the crankcase topped off as needed.
I have received the results of 3 analysis and the oil has came back each time "suitable for continued service".
 
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Oil has no idea how old it is.

Analysis will tell you when the oil is no longer serviceable, not the calendar. Is 6 years too long? I don't know; try it and see. Why don't you UOA once per year; track the wear metals and TBN and tell us how it goes.
 
Originally Posted By: dnewton3
Oil has no idea how old it is.

Analysis will tell you when the oil is no longer serviceable, not the calendar. Is 6 years too long? I don't know; try it and see. Why don't you UOA once per year; track the wear metals and TBN and tell us how it goes.


I suppose the same thing could be said for the dino oil I'm using now. If I add a bypass filter to keep the soot levels down, why couldn't it be run for four or five years? This fall, I will be testing the oil after a two year run.
 
It possibly could, Jim. I'd go so far to say as it probably could.


********** CAUTION - RAMBLING TO FOLLOW ****************

I run HDEO (Rotella 10w-30) in my 1966 289 Mustang because I don't want to change oil every year. I put very little mileage on it (summer top-down crusing on Sundays). I just changed the oil last weekend after 3 years (less than 1000 miles total). I choose dino HDEO due to the higher TBN and low cost; great combination.

I'm so confident in it that I don't even bother with a UOA. Why spend $32 for a Blackstone report when I can OCI for about $20? I suppose I could do a UOA, and see how the TBN holds up after 3 years, but what if it's OK for continued use? How many years would I go then? By the time I'd change oil, there would be a new revision level of HDEO (CK-4?), and I'd have to start testing all over again. Frankly, I don't care that much, regarding this particular vehicle. The 289 is a decent little engine, and what little I drive it, it'll last another 43 years. By then, my future grandson can worry about it ...
 
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Group I, II, and III oils are derived from dino oil basestocks. The dino oils are subject to shear. Once sheared the oil begins to breakdown. The true PAO ie Group IV basestocks are man made from a 10 molecular chain molecule. These group iv basestocks are difficult to shear. This is why extended drain intervals are possible. The only true PAO oils I know about are from Amsoil and Mobil. Many others simply hydro-crack dino oil to attain a group III class. Not a true synthetic my friends.
Even the new Castrol Edge is a group III with some PAO basestocks to get the low pour point ratings.
 
Let's not get into the whole "true" synthetic argument again, shall we not? It's a marketing term, and can be leagally applied for III, IV, and V. End of story. BTW - Mobil and Amsoil do NOT have the market cornered on PAO products; they are probably the largest producers, but in no way are the only producers.

Regarding your comment about shearing, that's certainly some portion of the story, but it's also very dependent upon the system is used in. Even PAOs will get sheared in a PSD HUEI system to some degree.

But, the OP was questioning about elasped duration of time, not mileage. The calendar means nothing to oil, only the use of oil. To that end, with low to moderate use, and testing for validation, a lubricant has the ability to go well past a couple years.
 
I would think, especially in a lightly used gas engine, that contamination from combustion & environmental humidity (condensation) would be your biggest concern-run it regularly, get the oil hot enough to evaporate/boil off the water, & I don't see a problem. I only change the oil in my 2 diesel pickups once a year, they just don't get driven enough (usually around 4K each).
 
I will refrain from getting into the "true " discussion. The 40k miles I referenced has taken me 3 years to log those miles. Based on the thread I am half way there.:)
 
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