On 27 Aug 2017 11:07:45 -0400, (Scott Dorsey) wrote:

In article , 83LowRider wrote:
On 8/19/2017 8:54 AM, Bram van den Heuvel wrote:

A study of automotive gear lubes
http://www.technilube.com/brochures/...hite_paper.pdf

Regarding synthetics in general --

"the AAA study didnt go light on the research and took a comprehensive
look into all the factors involved."

€œAAA found that synthetic oil outperformed conventional oil by an
average of nearly 50 percent in its independent evaluation, offering
vehicles significantly better engine protection for only $5 more per
month when following a factory-recommended oil change schedule.€?

This is good but... what does "synthetic" mean? A lot of the oils sold as
"synthetic" in the US are not in fact made from synthetic base oils at all,
just very highly purified ones.

And as it is, conventional oils vary considerably in their protection, because
the additive packages vary so much.
--scott
Don't know about the USA - but generally we get the same product in
Canada - and anything advertized as synthetic IS synthetic - but there
are several ways to synthesize a lubricant - including from
feed-stocks derived from petroleum - such as natural gas. If the
molecules are broken down into base components, and then blended and
reacted to produce a lubricating oil - the resulting oil IS synthetic
- whether the base feedstock is petroleum, natural gas, vegetable oil,
or any other source. There ARE specific types of "synthetics" that
some nerds and motorheads consider to be "more synthetic" than others.
- and some of them are NOT COMPATIBLE with some others, or with
petroleum based oils - which in MY books makes the "unsuitable" for
normal use - even if the "nerds" consider them superior.(Diesters vs
PolyEsters vs polyalphaolefin vs alkylated benzenes vs phosphate
esters,

Some are "group IV", some atr "group V" and some are "Group III" -
with the "Group III" being the most controvercial as they are 100%
petroleum sourced - with the feedstocks cracked from crude.

Many of the "nerds" consider only "Group IV" PAO oils to be "genuine
synthetic" - and PAO oils have long been implicated in seal shrinkage
and oil leakage.
Diester and Polyester based oils are generally unsuitable for
automotive and engine use -used in refrigeration oils, compressor
oils, some greases, and jet engine lubrication. They are also
implicated in seal incompatability.
Phosphate esrhers do not mix or get along well with petroleum oils and
are hard on most seals as well. Basically restricted to specific
hydraulic uses.
The poly-alkane Glycols also do not play well with othewrs -
particularly petroleum based lubricants,and are hard on seals and
finishes - used in hydraulics, compressors, refrigeration, and greases

"Generally" a GOOD synthetic oil for automotive use will be a
combination of several synthetics to produce the required
characteristics.