Why use Amsoil insead of Mobil 1?

[Mark Stevens <drtsqurt@pioneerplanet.infi.net>]

Amsoil is 100% synthetic ester, no dino. Amsoil may not have the
marketing punch of the major oil companies, but it's one of the main
reasons the majors even offer synthetic blends.
Last time I checked, Mobil 1 was 20% ester with the balance being dino.
Years back, Mobil 1 used to have a very small asterisk after their claim
of 100% synthetic. That caveat stated that Mobil 1 was 100% synthetic
"exclusive of base carrier oil".  When GM was specifying synthetic oil
for their Corvette and Cyclone engines, they didn't approve Mobil 1
until Mobil raised it's ester content from 15% to 20%. Most major brands
follow this path, they are actually semi-synthetic or para-synthetic,
meaning they are a blend of synthetic ester and dino.

Knowledge is half the battle,
Mark St. Paul, MN
*local auto parts stores around here sell Amsoil for $4.99/qt vs Mobil 1
at $4.49/qt