Corrections. posted by Spongerider :) on January 17, 2007 at 12:58 PM
Message
I would like to see the tech details of their tests but try to get them. Yes they follow ASTM specs but the fact is they choose not to get the API certification for all applicable vis blends except the noted few in the 2000 series. Why? It costs money. As I said that does not make Amsoil a bad oil but one should ask questions about their reasons other than cost for not getting the seal. Note again they did get it for selected 2000 series vis blends to meet auto manufactures and the publics requests for recommended oils for DDrivers.
BTW Amsoil does use greater than API starburst seal recommendations for zinc and phosphorous and this is done to provide max protection for possible metal to metal contact and this greatly helps the shear and 4 ball test results but cats are compromised. In fact their additive package is top secret. Note that Mobile 1 and others take the time and expense to get the API seal on appropriate vis blends.