huh...good to know. I used to be all M1, but now I am torn between Redline and Amsoil 10w30 (once I do go to full-synth). I decided not go M1 cause it is thin and not with the jerman juice because of its winter viscosity rating being out of Subie recommendations. As far as dino is concerned...would OEM Sub or Castrol be best? (or other than those).