Hammer said:
My Corvette buddy swears by Amsoil. Is he a dufus? Where can one find these testing results?
He's not a dufus, but Amsoil likes to play marketing games. Some of the issues I have with Amsoil:
- They stil use the four-ball testing method that has been out of date for many years. This test is easier to pass than more current testing methods such as FALEX (pin-vee anti-wear test).
- They use too much phosphate in their additive package which can poison catalytic converters. This has caused them to fail API testing for a long time. They have recently reduced the phosphate content so they are eligible to be tested.
- They are constantly changing their formulations. While there's nothing wrong with making changes to their additive packages or base formulation, severe changes like Amsoil does make me nervous. Too much change will can cause reactions that can attack soft metals in engines (such as the bearings) from non-compatiblity and cross-contamination (from the residual oil from the last fill).
- Amsoil doesn't have their own refinery which means they contract the lowest bidder to make their oil. I suspect that is why their formulation changes constantly.
- I have heard of quite a few people who have had issues with the additives falling out of suspension in the oil (thick residue on the bottom of the bottles or barrels). Good indication that there is either a reaction going on between the additive package and additive carrier, or there is a problem with the blender.
- Anti-wear tests are all over the place. Sometimes they test well, other times they do poorly or fail.
Amsoil has too many problems, IMO, to be used on a regular basis and to charge the price they do. If you want something exotic and expensive to run in your car, look at Case International diesel engine oil
