WindsorFox<[SS]> wrote:

> Amsoil meets or surpasses API specs, yes, according to them and one
> type is API certified. There is a difference between can not and
> refusing to provide some proprietary information.

No, Amsoil admitted, a long time ago, the reason why they don't have API
certification on some products. It has nothing to do with proprietary
information. They used do use the "proprietary" excuse because they
didn't want to admit the real reason, then one of their employees leaked
the real reason.

Here is the e-mail on this:
-----------------
From: "Selbrede, Byron" >
To: '" >
Subject: Technical Service Contact Form
Date: Mon, 14 May 2001 16:18:15 -0500

"Actually it's the amount of phosphorus that is regulated-- but
that is directly related to the amount of zinc that can be used as they
are combined as zinc dithio phosphate (ZDP). This is only regulated in 2
viscosity grades, 5W30 and 10W30. Other than the Series 7500, AMSOIL
lubes all contain more ZDP than can be used in an API licensed oil. For
examples of our ZDP levels refer to data sheets for AMO, ARO, AMF or AMV."
-----------------

The API limit on the amount of ZDDP was put in place because the
phosphorus in the ZDDP shortens the life of the catalytic converter; the
more ZDDP the shorter the life of the catalytic converter.

The high level of ZDDP in the Amsoil non-API certified oil (and some
other non-certified oils) provides better wear protection than the API
certified oils with the lower level of ZDDP. So it would make sense to
use these non-API certified oils in vehicles without catalytic
converters, in fact this is recommended. Or if you don't mind shorter
replacement intervals on the catalytic converter then it's fine too.

Contamination of the catalytic converter is a slow process. It will fail
earlier if you use oils with higher levels of phosphorus. You're not
going to be able to convince an oil manufacturer that their non-API oil
was responsible for a converter failing at 100K miles when it would
normally go 200K miles.

There's no reason to take the risk of using a non-API certified oil.