Radicool Si-OAT

A nitrite, amine and phosphate free antifreeze coolant with added silicate for the latest vehicles requiring silicate containing OAT technology. Aqueous solutions of Castrol Radicool Si-OAT act as both antifreeze and coolant and offer excellent corrosion protection to all metal parts found in the cooling systems of internal combustion engines.

Castrol Radicool Si-OAT should be used at concentrations of between 33% and 50% dilution with purified water to give optimum corrosion protection and freezing protection between -18°C and -36°C.


  • Excellent low temperature protection
  • Provides superior protection against all forms of corrosion
  • Minimises deposit formation, because of its phosphate free formulation
  • Approved for use in Euro 6 generation truck and bus engines