Originally Posted by prairiepedaler

Easy does it fella. There was no "question", an observational statement was made. As per the OP, the viscosity is different between the two "identical" products. I remember this difference clearly from using the older stuff from long ago. The older stuff had different viscosity even when it was purchased new.

In as clear a wording as I can make it: the new stuff doesn't last as long compared to the old. It's been thinned down. So, if there is some NOS old Tri-Flow bottles on a shelf somewhere, buy them, but only if good Tri-Flow is your thing.