Mixing dino & synth

[Al Powell]

"Tom Love" <theloves at localaccess.com> asked:

I've been told good and bad about mixing synthetic and dino lubricants to
our engines. Opinions and comments on this subject?

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You can do this if you want to - all you're really doing is creating
semi-synthetic oil, but in a random and unscientific way. As far as I know,
there is no oil chemistry problem with this, the oil just won't have the
extended wear limits, heat range or other characteristics of pure synthetic.
However, it will be somewhat superior to regular dino oil - that's why they
sell blends in stores.  If you need to do this in a pinch, or do it by
accident, it's not going to wreck anything. Just make your next oil AND
filter change at the recommended interval, choose one type of oil or another
(or buy a purposely manufactured semi-synth blend) and re-fill.

BTW - I have received a couple of thoughtful emails (and some less
thoughtful) off-list that assume I'm talking conventional motor oils down. I
am NOT trying to criticize conventional oils or imply that they leave your
engine dirty.  The chemistry and capabilities of all motor oils today are
vastly superior to what they were three decades ago. You can run any major
brand oil in your car and it will provide excellent service and help you
drive well over 100K miles provided that you do reasonable maintenance to
the vehicle.

My 1958 Fiat Roadster owner's manual says to use a castrol NON-detergent
oil, and no one in their right mind would do that today, if you could even
find non-detergent motor oil. All motor oils now are light years better than
the best oils available when that Fiat was made. But however good standard
motor oils are, I KNOW that synthetics are highly detergent and will leave
the inside of an engine as clean as possible. I simply assert that this is
one advantage of synthetics.

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Al Powell
apowell at gocougs.wsu.edu
1958 Fiat 1200 Transformabile Spyder
1983 Datsun 280ZX Turbo
1993 Audi 90Q
1997 Chebby Blazer
1999 Chebby Blazer
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