Old Amsoil basestock and OCI's

[addyguy]

Ok, Amsoil folks, here's one for you:

When Amsoil first came out in 1972, it was an ester-based 10W-40 oil, that was advertised to do 25,000 mile changes, right from the start. Amsoil still advertises 25,000 change intervals, but know proudly proclaims it is a PAO-based oil, so at some point the basestock changed.

One thing that has been discussed on this forum is that predominantly ester-based oils (Redline being the best modern example) are great as oils for extreme performance situations, but not necessarily as good for extended OCI's. But at one point, Amsoil did use them for this.

Did Amsoil change its basetock to PAO because of this, and if so, when did they do this? If they didn't change the basestock b/c of this, and did it for cost or some other reason, then maybe ester-based syn oils actually ARE good for extended OCI's? How did early, ester-based Amsoil compare in long drains to the PAO based product?

Interested to hear facts on this......

 

[TeeDub]

As I recall, they changed to blended PAO/Ester basestocks in the early 1980's, the PAO's being purchased from Mobil Corp. The reason was to get the best overall combination of physical/chemical properties, including compatibility with additive chemistries primarily developed for conventional oils.

Most of the R&D work in additive technology was and is based on use with petroleum basestocks, and these same chemistries work extremely well when combined with PAO's. By contrast, the add pack needed for a diester or Polyolester basestock is very different. So you can't leverage the money put into additive research as directly if you go the ester route.

I started using the 10w-40 and 30wt diesel Amsoil formulations in the spring of 1978, when it still was a diester based product. I found it to be excellent in terms of engine cleanliness. However I never ran it longer than about 15,000 miles, so I can't speak for the performance after that. I can say it was so much better than the conventional oils of the time it was like night and day.

TD

 

[buster]

In addition to what TD said, oils such as RL/Motul use PAO in their street oils, however at a lower dose. A lot of it comes down to the chemist and his/her formulating philosophy. This is what the guy's from Maxima will tell you.

If cost is of no concern, some say all ester based or majority ester based would be most ideal, some would say a combination. Each base oil has specific qualities that are ideal and it's the balance achieved between the additives/base oils that make an oil good/bad.

I specifically asked Elf about this and they said that their 2 Stroke oils are ester based, automotive 4 stroke are PAO based. Elf's F1 oil's are all majority PAO.These engines hit 21,000 rpms. They claim that "esters" are used as a marketing tactic to make you think an oil is superior bc it contains "esters". Mobil 1 R is majority PAO. PAO/Ester blends seem to give you the best overall performance. For a Jet Engine, an Ester based oil would be best. I believe Motul's own website stated that more than 20% ester is not needed.

 

[Pablo]

Actually it seems to me Amsoil changes basestocks (within group or some group IV - V blends) on average about every 2-3 years. While I can't fix dates on these change and a lot of the so called (web) history is shrouded in time fog, it is said the early diesters were extremely prone to leaking and did indeed have some additive issues. This is one reason Al ended up going to Hatco.

Modern ester engine oils are fine for the long haul as are the slightly more economical PAO/Ester blends.

I agree with Ted - the differences between the early synthetics and Group 1 oils was huge.

 

[Tom NJ]

Not an Amsoil dealer but I am familiar with some early history. Their early motor oils were based on esters and performance was quite good. Presumably PAOs entered sometime in the 1980s.

In the early/mid 1980s there was a glut of PAO on the market and prices plummeted, so there was plenty of cost incentive to use PAOs. Likewise there was technical incentive as well since a PAO/ester blend gives a nice balance to seal swell properties, and most people went that route.

Today the esters remain considerably more expensive than PAOs, and even less attractive compared to Group IIIs, so their use is minimized in motor oils. But from a technical standpoint, one can make one heck of a motor oil from all ester basestocks and modern additives, especially utilizing some special high lubricity POEs. Seals, however, could remain a potential problem. If someone could build an engine with ester compatible seals, I could build a super oil to go with it, but unfortunately not enough people would pay the price to make it a feasible project. Alternatively, a PAO/POE combo with perhaps 40-60% of some special POEs and a robust additive system would be next best with existing seals, but also somewhat pricey.

Fact is the majority of the motor oil buyers are price driven and not willing to pay for performance they cannot perceive. Most people only see the oil on the dipstick, and they all look the same - dark and smelly. Only BITOGers can feel one centistoke, measure a 2% fuel efficiency, see sediment in the bottom of a bottle, and cook pennies in oil!

If only we all were more than 0.001% of the market…

Tom

 

[addyguy]

Thanks for all the info - some interesting stuff there!

 

[427Z06]

Quote:

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Alternatively, a PAO/POE combo with perhaps 40-60% of some special POEs and a robust additive system would be next best with existing seals, but also somewhat pricey.

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I wonder how many people believed/still believe they were/are getting a product of that performance level when they grab for that bottle of M1.

Quote:

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Fact is the majority of the motor oil buyers are price driven and not willing to pay for performance they cannot perceive. Most people only see the oil on the dipstick, and they all look the same - dark and smelly. Only BITOGers can feel one centistoke, measure a 2% fuel efficiency, see sediment in the bottom of a bottle, and cook pennies in oil! If only we all were more than 0.001% of the market

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Yep.

 

[TeeDub]

One thing I remember very clearly about those ester based Amsoil formulations is that they cleaned out deposits like crazy, in engines that had been running Group I, petroleum oils. You had to change out the oil filter within a few thousand miles the first time around, or it could become saturated with sludge. This was the reason why Amsoil came out with their engine flush in the 1980 timeframe. The previous changeover procedure called for putting on a new oil filter, draining some of the old oil,adding one quart of Amsoil to the crankcase, then running this for 1000 miles, prior to doing the changeover. What they found was that this procedure (similar to an ester based, ARX treatment), did not fully clean out the sludge/varnish/gum deposits. As a result, that first batch of Amsoil could still get very dirty within 10,000 miles of use.

The other thing I remember about the esters is that they would form a whitish powder on the inside of the exhaust pipe when they burned.

TD

 

[Tom NJ]

Quote:

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The other thing I remember about the esters is that they would form a whitish powder on the inside of the exhaust pipe when they burned.

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Hmmm, that's interesting - I had never heard of that. Some of the early formulations did contain Trimellitate esters which, in theory, could sublime in the cylinder to give trimellitic acid (a white powder), but I am speculating here.

Tom

 

[TeeDub]

Tom,

Actually it was more of a grayish/white color, as I recall, but it was very noticable in older V-8's of the day that burned oil....

Ted

 

[mitchcoyote]

HAIL Amsoil!!!.... HAIL Amsoil!!!.... HAIL Amsoil!!!....

 

[Mamala Bay]

Amsoil is the best for extended drain intervals. I don't know all the technical stuff as some folks do but just like the way it performs. I use nothing but Amsoil.