From a UOA point of view,not a virgin sample of coolant), it seems that more boron is being used as an additive and confirmed in the UOA, at least with Amsoil, around 25-30 ppm. Used to be almost nil. Also, if you are burning the coolant via a head gasket leak then the boron may be elevated but difficult to tell. Potassium appears that under 5 ppm is the norm and sodium under 10 seems about right. If you have higher numbers, coolant level in overflow tank is consistently low and you may also see higher lead numbers then a coolant leak is feasible and worth checking out.
[ October 26, 2003, 12:06 PM: Message edited by: Spector ]