[s-cars] Re: Mobil 1 0W40

[Pram]

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On Sunday, March 2, 2003, at 09:53 PM, CyberPoet wrote:

> One other related note: Castrol at one point decided to blend a
> synthetic and non-synthetic oil and label it as a synthetic oil without
> reference to the fact that it was a blend. They had figured out how to
> match additives to traditional oils and get them to perform as if they
> were pure formulated synthetics (the conversion process cost them about
> 50% of the product cost of generating a pure synthetic). Naturally,
> they were promptly sued by a competing automotive oil firm (I think it
> was Mobil; the plaintiff  felt it was a deceptive practice). The result
> of the lawsuit with Castrol as the defendant, was an official court
> decision that mix-blends can still be claimed to be synthetic if they
> contain a synthetic portion, without regard to the actual percentages
> of synthetic vs. traditional dino oils. The consequence has been that a
> number of firms are now blending traditional and synthetic oils and
> labeling them as synthetic oils.

Actually, if I am not mistaken, the lawsuit was not because Castrol
decide to blend synthetic and non synthetic and labelled them as
synthetic.  It is due to the fact that Castrol was using highly refined
(type 3 hydrocracked) mineral based oil as their Castrol Syntec.  The
court ruled in Castrol favor though, allowing the additional processing
of the mineral based oil to qualify the end product as "synthetics"


> Most synthetic formulations use an uncurling long polymer chain that
> changes the effective viscosity (upwards) as the temperature rises, but
> the reference weights listed on the package do not refer to that in any
> sense, as the API's standards for the rating does not include that
> information.

Actually AFAIK,  most multi-weight oil uses "uncurling long polymer
chain" (or normally called viscosity extender).  A 0W-40 oil is
basically made using 0W based oil with viscosity extender so that it
will act like a 40W based oil at higher temperature.  The  more
homogenous nature of the synthetic base as compared to regular fossil
based lubricant which contain impurities (hydrowaxes) lend itself to
viscosity property that is less affected by temperature hence the need
to use less quantity of viscosity extender.   The disadvantage of the
viscosity extender is that with time (due to heat and shear) they will
break down resulting in the oil not to have the 40W (using the 0W-40 oil
as the example) viscosity at the higher temperature.  This will result
the oil having less ability to mantain film strength at higher
temperature.

Certain multi-weight synthetics actually claim to contain no viscosity
extender.  One of the other side-effect of the viscosity extender is
that it reduces the slipperiness of the oil (just like the addition of
detergent in the oil). Which is why race oil usually does not contain
detergent and viscosity extender (oil become single weight then) to
maximize horsepower by reducing friction.


HTH,
Pram
92S4

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