Synthetic Oils

[jadney@vwtype3.org (Melissa & Jim)]

>From the few posts that we have seen here it is easy to see why the jury is 
still out on synthetic lubricants.  As you can see, we have a few examples 
of its use, some with happy endings, some otherwise.  Everyone would like to 
extrapolate from their (usually singular) experience to a generalization 
that synthetics are <insert favorite adjective here>.

The point is that there is nothing to be learned from a single experience, 
even if it is a good one that lasts 100k, although that would be somewhat 
supportive. It seems unlikely that their physical properties of would 
support the contention that synthetics don't carry heat well, since even 
petroleum oils are only fair at it--compared to water.  Specific heats of 
liquids are easily measured and would be known to the manufacturer, and they 
tend not to vary that much from fluid to fluid.

I think it was Keith who had the really bad experience.  Yet there is no way 
to know if the synthetic was responsible for his problem or if the problem 
just happened to go away at about the same time that he changed his oil.  
Could there have been some out-of-spec part that finally wore in?  Or was it 
a bad batch of synthetic oil that ruined his engine where the problem was 
really poor quality control on the part of the manufacturer but not an 
indictment of synthetics in general?

For those who have no oil filters, I can see no reason to switch to 
synthetics. For those with filters, well who knows?

The good news is that petroleum oils have significantly improved since our 
cars were new.  Because of higher operating temperatures in modern water 
cooled cars, modern oils have to tolerate temperatures that have always been 
common in our air cooled VWs.  I have Type IIIs with and without filters, 
and I still just use petroleum: 10W-30 in the winter and 10W-40 in the 
summer.  I change it in the spring and the fall.  I could probably do better 
by just stocking 10W-30 for year 'round use.

Jim
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       Melissa Kepner                                    Jim Adney
       jadney@vwtype3.org              jadney@vwtype3.org
                             Laura Kepner-Adney
                             Madison, Wisconsin
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