The story I heard was that during the
war (WWII), it was in the newspapers,
the Germans were trying to produce an
oil additive that would add or prolong
the life of petroloeum products for
lubricating machinery.  STP was such a
product, in the 50's only 8 years after
the war at dealers you would find dealer
racks that said GERMAN DEVELOPED. But
back to the war. As the story goes they
needed a scientific basis to measuer the
viscosity over a run of this stuff.

One thing they had plenty of was a
cetain sized screwdriver,  and they
would take one of these screwdrivers and
drop it into a large  glass beaker of
STP and time the time it took for hte
screwdriver to reach the bottom. if you
spleak German, I believe the word for
screwdriver is somewhat close, but it
became known as the  SCREWDRIVER TESTED
PRODUCT.

BG

The story I heard was that during the
war (WWII), it was in the newspapers,
the Germans were trying to produce an
oil additive that would add or prolong
the life of petroloeum products for
lubricating machinery.  STP was such a
product, in the 50's only 8 years after
the war at dealers you would find dealer
racks that said GERMAN DEVELOPED. But
back to the war. As the story goes they
needed a scientific basis to measuer the
viscosity over a run of this stuff.

One thing they had plenty of was a
cetain sized screwdriver,  and they
would take one of these screwdrivers and
drop it into a large  glass beaker of
STP and time the time it took for hte
screwdriver to reach the bottom. if you
spleak German, I believe the word for
screwdriver is somewhat close, but it
became known as the  SCREWDRIVER TESTED
PRODUCT.

BG

And be sure to insert in the
instructions to apply liberal coats of
STP to rotors and calipers once they are
installed.   :)

BG