The simple answer is HOAT is backwards compatible with old ethylene glycol where OAT isn't! It's all to do with the silicate mixing capabilities! I went on a very very boring course regarding coolants! if you put OAT in an old cast engine designed with ethylene glycol in mind it does rot rubber seals & joints (I do have personal experience of this) & if you put old type coolants in an all alloy engine even with distilled water they do fur up & don't stop alloy corrosion!Hope this helps!
No chemical sh*t in it.
Quote from: UKJeeper on February 01, 2013, 05:50:56 PMNo chemical sh*t in it. apart from the stuff in chemtrails, google it