Andy wrote:
>> >>
>>
>>>Andy wrote:
>>>
>>>>>>>>
>>>>
>>>>>Andy wrote:
>>>>>
>>>>>>>>>>>>
>>>>>>
>>>>>>>Note that the other Amsoil products, while they cannot be API certified
>>>>>>>due to the ZDDP level, do use synthetic base stock. Don't use them in
>>>>>>>vehicles with catalytic converters, despite what your local MLM person
>>>>>>>may tell you. Mobil 1 EP does use synthetic base stock.
>>>>>>
>>>>>>They have no effect on catalytic converters. I have no idea where you
>>>>>>came up with that one.
>>>>>
>>>>>Never use a non-API certified synthetic oil (there are many of these on
>>>>>the market) in a vehicle with a catalytic converter. The problem with
>>>>>the non-API certified synthetics is that they contain too much
>>>>>phosphorus (in the form of the additive ZDDP (Zinc Dialkyl
>>>>>Dithiophosphates)). The API has limited the amount of phosphorus because
>>>>>phosphorus shortens the life of the catalytic converter. These oils are
>>>>>fine for snowmobiles, motorcycles, and older cars that don't have a
>>>>>catalytic converter, and the extra ZDDP does provide additional wear
>>>>>protection.
>>>>
>>>>What proof do you have of this?
>>>
>>>An Amsoil factory representative wrote (I deleted the names because I
>>>don't want him to get in trouble for telling the truth, but the
>>>recipient of this e-mail posted it on Usenet where I saw it and you can
>>>find the original using Google Groups):
>>>
>>>------
>>>
>>>From: "xxxxx, xxxxx"
>>>To: "' snipped-for-privacy@pinn.net'"
>>>Subject: RE: 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. >>>
>>>------
>>>
>>>
>>>It's actually ZDDP, not ZDP, but the Amsoil representative got it right
>>>and it's the first time that we've seen the real reason that Amsoil
>>>couldn't get API certification on their products (other than the XL-7500
>>>which doesn't have as much ZDDP) This limit was set by API because too
>>>much zinc will shorten the life of the catalytic converter. If you have
>>>an older vehicle without a catalytic converter (or a motorcycle, jet
>>>ski, snowmobile, etc.) then the non-API certified Amsoil lines are okay
>>>(but still outrageously priced).
>>>
>>>I'm sure that you really do understand all this, but for some reason
>>>you're being deliberately obtuse about it. I have no dog in this fight,
>>>and don't care what oil you use, but you should at least understand the
>>>differences between different synthetic oils, their base stocks, and
>>>their additives.
>>
>>
>>
>> So where is the proof that it hurt catalyitc converters? I'm not
>> saying Amsoil doesn't use more ZDDP, just that I don't agree it hurts
>> the catalyitic converter.
>
>
>As cheap as GM is, it wouldn't not use ZDDP if they could absolutly help
>it. The reduction of ZDDP in motor oil forced them to change to roller
>lifters. If you've got an old classic pre-cat car with flat tappets and
>want to use modern low ZDDP oil, go to your GM dealer and get some EOS.
Or simply use AllFleet oil like Shell Rotella.