In a prior vehicle (48 Dodge) I tried full synthetic 85wt in the tranny. Only negative I noticed was I had to wait to downshift to first (non syncro). Prior to the synthetic, I could stop at a light and downshift from 2nd to 1st right away. With the synthetic, when first stopped, if I downshifted immediately the gears would clash - found I had to wait for several seconds to go into first. I assumed the synthetic worked so well there was still gears spinning in the gearbox.
