Thanks all for valuable inputs!
I have been trying to search the web for the details of different coolants especially the CALTEX.
In summary the Caltex coolant is an EXTENDED LIFE coolant and alot of places recommended 5 years / 150,000 MILES.
This is because it doesn't have Silicates, Borats or Phosphates in it.
It has the O.A.T (ORGANIC ACID TECHNOLOGY) which is kind of the latest thing out!
But I guess if one really want the maximum mileage out of this coolant one has to use DeIonized and De Mineralized water OR Get a pre-diluted version from the Caltex guys!
Thanks again to all!