Originally Posted by
GraphiteGhost
Only additive I ever add to a motor is STP oil treatment (as it coats the parts some so they do not 'dry start' when first cranking). This first cranking 'dry start' is where damage to bearings/moving parts occurs. Oil companies do not add this type of thing because it costs them money. Before I started adding this to the XF, I got confirmation from Mobil1 and STP, by email, making sure they were 100% compatible.
Dry start? I doubt that any of these cars start dry. Oil sticks to everything, the cylinder walls have a microscopically thin layer of oil on them and bearings do not squeeze out the oil on their surfaces. I can imagine that it is compatible so is other synthetic and dyno oils and STP is made to be compatible or it would be bad for business.