Molakule has graciously given great descriptions on the operation of the common ash based or metallic AW addtives, such as MoDTC, ZDDP, SbDTC, Boron, overbased calcium, etc. And we now have a pretty clear idea how they work. But, how do the ashless AW additives work? They may have been briefly mentioned as to the fact that they exist, but we have never discussed what they are and how they work. We have discusssed ashless FM and antioxidants but not AW. Been wondering for a while but what also prompted more interest was a quote on Valvoline's website regarding the VR1 oil: "New ashless anti-wear additives combined with ZDDP provide ultimate wear protection" If anyone has any info for discussion, please share. Otherwise, hopefully Molakule will chime in.