Originally Posted by Subdriver

Very simplistic to say they get their product from another company, implying they rebadge and sell it. Motor oil is blended together from many constituents, primarily the basestock and additives including anti-wear additives, dispersants and detergents. How these are all blended together differentiates one oil from another. AMSOIL has its own plant where the basestocks and additives they buy from other companies are blended together to make the final products.

The API has not defined "synthetic". It is accepted that Group III basestock (highly hydroprocessed mineral oil), Group IV (polyalphaolefins or PAO), and Group V (all others including polyol esters) are "synthetics". The majority of the synthetics on the market are Group III. All of AMSOIL's lubricants less the XL line use Group IV basestock. But, even that is simplistic. Go to Royal Purple or Mobil 1's website and try to determine what basestock they use. RP doesn't say and Mobil 1 uses vague language like "uses high-performance fluids, including polyalphaolefins (PAOs)." So is their basestock PAO or partially PAO or mostly PAO? Hard to tell. AMSOIL is believed to use primarily PAO, but with some percentage of Group V polyol ester added in to lower the oil's coefficient of friction and improve its compatibility with seals. As to how much, they aren't saying.

The additives are equally varied, and in many cases, particularly for API SM oils, limited by the API guidelines. For example, 30 grade oils labeled to meet API SM/ILSAC GF-4 requirements are limited to having phosphorus less than 800 ppm. As phosphorus is part of an oils primary anti-wear additive, along with zinc, that is why I don't use an API SM oil in my Z06 on the track (I use AMSOIL Dominator racing oil with zinc on the order of 1575 ppm).

So, in a roundabout answer to your question, AMSOIL buys basestock from major oil companies but they vary who they buy from to get the best balance of price/quality. They buy additives from chemical companies. They blend them all together at their processing plant in Superior WI and ship their product out to distrubution centers from there.

I've taken a few oil samples on my daily driver, an 06 CTS-V with the LS2 engine. You can see the differences between the Mobil 1 and AMSOIL in these results (such as the higher Calcium levels - a detergent). AMSOIL is not a rebadged version of Mobil 1 or any other oil.
Cadillac CTS-V Used Oil Analysis – Mobil 1 5w30 vs AMSOIL 0w30

In answer to the questions above about what retail outlet can sell AMSOIL, the short story is that AMSOIL will not distribute to nationally owned chains like Walmart. They will to locally owned businesses (usually limited to an owner who owns 12 or less stores). Most NAPA stores are locally owned so they qualify for AMSOIL retail accounts. FYI, if anyone owns a business that either uses or sells oils, getting an AMSOIL account is easy and there is no cost to businesses for this account. PM if interested.

Originally Posted by Subdriver

Very simplistic to say they get their product from another company, implying they rebadge and sell it. Motor oil is blended together from many constituents, primarily the basestock and additives including anti-wear additives, dispersants and detergents. How these are all blended together differentiates one oil from another. AMSOIL has its own plant where the basestocks and additives they buy from other companies are blended together to make the final products.

The API has not defined "synthetic". It is accepted that Group III basestock (highly hydroprocessed mineral oil), Group IV (polyalphaolefins or PAO), and Group V (all others including polyol esters) are "synthetics". The majority of the synthetics on the market are Group III. All of AMSOIL's lubricants less the XL line use Group IV basestock. But, even that is simplistic. Go to Royal Purple or Mobil 1's website and try to determine what basestock they use. RP doesn't say and Mobil 1 uses vague language like "uses high-performance fluids, including polyalphaolefins (PAOs)." So is their basestock PAO or partially PAO or mostly PAO? Hard to tell. AMSOIL is believed to use primarily PAO, but with some percentage of Group V polyol ester added in to lower the oil's coefficient of friction and improve its compatibility with seals. As to how much, they aren't saying.

The additives are equally varied, and in many cases, particularly for API SM oils, limited by the API guidelines. For example, 30 grade oils labeled to meet API SM/ILSAC GF-4 requirements are limited to having phosphorus less than 800 ppm. As phosphorus is part of an oils primary anti-wear additive, along with zinc, that is why I don't use an API SM oil in my Z06 on the track (I use AMSOIL Dominator racing oil with zinc on the order of 1575 ppm).

So, in a roundabout answer to your question, AMSOIL buys basestock from major oil companies but they vary who they buy from to get the best balance of price/quality. They buy additives from chemical companies. They blend them all together at their processing plant in Superior WI and ship their product out to distrubution centers from there.

I've taken a few oil samples on my daily driver, an 06 CTS-V with the LS2 engine. You can see the differences between the Mobil 1 and AMSOIL in these results (such as the higher Calcium levels - a detergent). AMSOIL is not a rebadged version of Mobil 1 or any other oil.
Cadillac CTS-V Used Oil Analysis – Mobil 1 5w30 vs AMSOIL 0w30

In answer to the questions above about what retail outlet can sell AMSOIL, the short story is that AMSOIL will not distribute to nationally owned chains like Walmart. They will to locally owned businesses (usually limited to an owner who owns 12 or less stores). Most NAPA stores are locally owned so they qualify for AMSOIL retail accounts. FYI, if anyone owns a business that either uses or sells oils, getting an AMSOIL account is easy and there is no cost to businesses for this account. PM if interested.

Originally Posted by Subdriver

Very simplistic to say they get their product from another company, implying they rebadge and sell it. Motor oil is blended together from many constituents, primarily the basestock and additives including anti-wear additives, dispersants and detergents. How these are all blended together differentiates one oil from another. AMSOIL has its own plant where the basestocks and additives they buy from other companies are blended together to make the final products.

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Originally Posted by 07c6vette

Whatever happened to the re-evaluation results on the insolubles? Thanks

" We're a little concerned with the increase in insolubles from 0.3 to 1.3%. Despite the engine's relatively low life, this may be attributed to sludge buildup that was cleaned out by the AMSOIL's increased level of detergent (3193 ppm Calcium vs 2588 for the Mobil 1). We intend to follow Blackstone's advice and change out the oil at around the same periodicity and re-evaluate the insolubles at that point. "

Originally Posted by Subdriver

Here is the latest oil sample from my 06 CTS-V:
Cadillac CTS-V Used Oil Analysis AMSOIL 0w30

Those interested in that might also be interested in the results of the tranny fluid sample:
2006 Cadillac CTS-V Used Oil Analysis Dexron III vs AMSOIL ATF Transmission Fluid

I had the last version of the AMSOIL ATF in my CTS-V and didn't really plan to change it out that early, but AMSOIL changed their primary recommendation for the manual tranny from the ATF to the AMSOIL Torque-Drive Synthetic Transmission Fluid (ATD) so I wanted to try it so I could recommend it in good faith to those asking about it. I really couldn't tell the difference between these two fluids. I was pleased to see that the AMSOIL ATF had no viscosity shear down over the relatively short 6300 mile sample interval, as compared to the stock Dexron III which dropped from about 7.3 to 5.0 in 10k miles.

And, FYI, last month AMSOIL increased the viscosity of the ATF to put it back squarely in line with Dexron III viscosity (its now 7.6 cSt at 212F) and came out with a new low viscosity fluid for Dexron VI applications: AMSOIL Low Viscosity Universal Automatic Transmission Fluid (ATL)

AMSOIL's tranny fluid recommendations are now:
Manual (Dexron III applications):
Primary: AMSOIL Torque-Drive Synthetic Transmission Fluid (ATD)
Alternate: AMSOIL ATF

2006 and on automatics (Dexron VI applications):
Primary: AMSOIL Low Viscosity Universal Automatic Transmission Fluid (ATL)
Alternate: None

2005 and earlier automatics (Dexron III applications):
Primary: AMSOIL ATF
Alternate: AMSOIL Low Viscosity Universal Automatic Transmission Fluid (ATL)

Originally Posted by LS WON

It looks like for the 2005 the alternate Amsoil would be a better choice than the universal? Or does it matter?

Originally Posted by Subdriver

AMSOIL is recommending the ATF over the ATL for those trannies that originally had Dexron III recommended. The primary difference is going to be the fluid's viscosity. The ATF has a viscosity of 7.6 cSt at 212F and the ATL has 6.0 cSt at 212F. Given the stress the A4 tranny puts on a fluid, and the temps that it could reach, I personally would follow AMSOIL's recommendation and use the ATF for Dexron III automatic applications like yours given its higher viscosity.

Originally Posted by LS WON

So get the Universal ATF vs. the one that says for Dex 6?
In layman's terms, the Universal ATF can withstand higher temps?

Originally Posted by Subdriver

Your tranny was designed to use Dexron III and the Universal ATF has a viscosity that matches that of Dexron III. The Dexron VI has a lower viscosity, primarily to save a little on GM's CAFE.

As a spec, the Dexron VI requires a better basestock (most believe at least a semi-synthetic blend is required to meet the Dexron VI specification) than the Dexron III. But in the case of the AMSOIL, you are getting a top notch Group IV PAO basestock with either the ATF or the ATL so they both far exceed the spec.

The primary difference is going to be the viscosity. The Dexron VI has a lower viscosity. Given how hot the Corvette automatic transmission can get, and noting that any fluid's viscosity drops as it heats up, I'd go with the higher viscosity fluid - in this case that is the one your owner's manual specifies - the Dexron III fluid (and in this case the AMSOIL ATF).

Originally Posted by LS WON

The Amsoil Universal ATF is a fully synthetic blend unlike the Dexron III or semi-synthetic Dexron 6 right?

Originally Posted by Subdriver

The AMSOIL ATF uses a Group IV PAO basestock. Not a blend or a semi-synthetic. And yes, the ATF has been around for years and I've got numerous customers running it in their automatics and none that I remember has reported any problems.