Practically Classics Forum

MPG/Propylene glycol isn't damaging to older cooling systems so no need to worry there, and there are some (but not nearly enough) brands of MEG whose makers are already using Bitrex. Fuchs "Eskimo" which is supplied by Opie oils among other sellers, has Bitrex but some don't like Eskimo because it's only very slightly tinted (purple) so isn't seen as easily if it leaks as the blue or green types are.
Suppliers of Propylene glycol-based coolant include these people who'll post it and have sold the product to several colleges for use by their motor vehicle engineering departments, whose students have been known to try drinking pretty much anything. This stuff isn't brightly coloured either but you could safely add some food dye if that's a deal breaker.

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

Tapwater will be fine- no need for anything else. I live in an area where the water is so hard it could do Chuck Norris blindfolded but, as with central heating systems, there being a fixed quantity of water in there, limescale won't be a problem..............unlike the kettle which is constantly needing descaling

For antifreeze I generally tend to use whatever's blue and reasonably priced in the spares shop - the jury's still out on OAT but that's usually a bit too pricey for me anyway!

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.

advice taken and product ordered JPB.

Many thanks, kev

I looked at this subject some time ago when trying to make a decision about the "right" kind of antifreeze for my 1937 Daimler 15 Sports Saloon.

In summary, my view is:
1. Best choice is Propylene Glycol, but it has to be used at minimum 50/50 mix with water. PG is kind to the environment & is used in household central heating systems because it is relatively benign. Seems to cost about 10% more than Ethylene Glycol per 5 litre pack and is readily available from plumbers merchants.
2. Next best choice is OAT Ethylene Glycol antifreeze (Organic Additive technology) such as the old Bluecol brand; but beware, not all blue antifreezes are OAT. Again, the best concentration is 50/50 mix. Problem with EG is that it is unkind to the environment, can ruin paintwork, etc.
3. Do not use IAT antifreeze (Inorganic Additive Technology) modern stuff in classic cars for a variety of reasons including bearing corrosion in water pump bearings.
4. I also read a technical paper that suggested that tap water would be preferable to de-ionised water, but water from dehumidifiers etc. is OK.

A friend of mine is using waterless coolant in his 1965 V8 Daimler. it looks like the best option for many classic cars, but pricing and availability make it less attractive to me.

Best wishes, Dave B

I went for Propylene Glycol USP/EP GRADE and filtered tapwater in the end.
Never really understood antifreeze untill i started this thread. You read about the lubrication it provides in addition to the obvious antifreezing and anti=corrosion qualities.
The product i used is quite gloopy so im assuming that is what gives the lubrication..unsure of the anti-corrosion...do i need to put a further additive in JPB?

Kev

No. In an engine of that age, no matter how clean its cooling system, there's bound to be some scale build up that would be best left where it is. Start pushing extra anti corrosives through and you run the risk of loosening that scale.
Wit MPG in the system, that layer of lime won't build further but nor will it be attacked so that will, in itself, provide an effective barrier to corrosion. Unlike MEG/water mix, MPG/water mixture is not corrosive and that further reduces the risk as well as minimising any need for additives.

I read somewhere that tap water isn't ideal,as it contains ions. I've recently put in my Cortina pure antifreeze from Unipart (£15 for 5 litres),as it was given just water from the last owner

PLEASE tell me you are kidding.
bit of information on ions: http://en.wikipedia.org/wiki/Ion
running your car on 100% antifreeze is a very, very, very bad idea
http://autorepair.about.com/library/a/1b/bl174b.htm
not 100% accurate but gives you an idea.

You can get water free coolant which is fine bit anti-freeze is not intended for that job.