kevin wrote:is this definately the stuff?
5 LITRES MPG Propylene Glycol USP/EP GRADE
apart from the environment aspect, is it ok to use in an older engine with alloy head?
kev
That is absolutely
perfect for the job. Don't be put off by its absence of bright colour or its "Medical Grade" status which is mentioned simply as that is more significant to those who buy it for use in pink gin-making ingredients, electric fags and the essential smelly oil market. Your car's cooling system will behave in exactly the same way when filled with a 30% solution
(50% would be safe and would provide an even lower freezing point but at the expense of the ability to keep the engine cool in hotter conditions) of this product as it would if that 30% were made up of a Mono Ethylene Glycol based liquid, but without the risks to animals that exist in the use of MEG-based coolant. The addition of Bitrex to MEG does put off those animals as the sweet taste of the MEG is what they like about it and, in a cooling system that's free of leaks as I hope that of your beautifully kept car will prove to be, then no leaks = no immediate risk however MPG may, when the time comes to change it for fresh, be disposed of by simply pouring it down the nearest drain.
I found a company that sells the stuff with the marketing slant being toward the automotive sector and if you have a quick read of
this, it backs up my answer to the question of its suitability for an alloy headed engine such as yours.