synthetic/organic oil mixture

[Keyton Guthery <keyton@xxxxxxxxxxxxx>]

I realize the topic of synthetic motor oil has been beaten to the point of
loss of viscosity, but I have a new (to me at least) question on the topic:

My newly acquired e30 with 65k miles is nearing its first (in my
possession) oil change and I had plans for synthetic oil.  My mechanic
suggested that I go with 50/50 mixture of synthetic to organic due to his
claim that synthetic has some benefits unavailabe in organic and organic
has some benefits unavailable in synthetic - since to two mix well, going
with a 50/50 ratio gives me the best of both worlds.  Knowledgable Opinions
Please?  

Also could someone elaborate on the potential problems I have heard about
cropping up when you switch to synthetic and the rear main seal begins to
leak?

Thanks,


Keyton

90 325iC
88 300SEL

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