Every time someone brings up the subject of the latest and greatest oil additive, I think back to my college days and my Fuels and Lubricants lab. Back then the big name in oil additives was STP, and during one lab session where we were testing motor oil viscosity we decided to try a little STP. We mixed the STP with the 10w30 motor oil in the appropriate volume (I believe it was 10%) and performed the viscosity test at 212°F first. Then we chilled the mixture down to 0°F and attempted to test the viscosity. The test had to be aborted, since the mixture was almost solid and it stalled the equipment. Just what you needed in your crankcase in the middle of a Michigan winter.
As stated earlier, leave the chemistry to the oil professionals.
Jerry