distilled or deionised to mix with anti-freeze?

[Magicarcher]

Hi I want to replace my coolant for the winter. A dilemma I have is do I mix the anti-freeze with distilled water or deionised water. Most sites suggest using distilled water mixed with anti-freeze. Comma suggest using deionised with their G48 anti-freeze.

Distilled seams less widely available than deionised which can be bought at Halfords, Eurocarparts, B&Q. But I had read an article that suggests that deionised water can still have impurities. It is just the ionic state that has been changed. Any water experts out there?

[Ducklakeview]

If you have a condenser tumble dryer with a water container, use that water.

Don't forget that the the lack of ions in deionised water makes it particularly corrosive and I wouldn't use it in any of my vehicles.

Mike

[Crazy Harry]

I use water from a dehumidifier. In fact I have been known to fill a water drum ready for a coolant change

[rally-chris]

Can’t you just buy ready mixed coolant and do without the need to add extra water of any sort?

[MJJamieson]

BMW say tap water???

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[GuidoK]

Don't forget that the the lack of ions in deionised water makes it particularly corrosive and I wouldn't use it in any of my vehicles.

As soon as you mix it with coolant it'll be full of ions in massive concentrations. Coolant mix has anticorrosive salts in them (like sodium tetraborate).
So using deionised water to add to the coolant mix has no risks. But tap water is just as good and cheaper as long as there's not too much chalk in it (limescale could theoretically be formed).

[Crazy Harry]

BMW say tap water???

page23image2884704 copy.png

Hadn't seen this but living in a very hard water area the only stuff I trust has been through the dehumidifier first - I filter drinking water but wouldn't put that in the cars!

[MACK]

Does seem like over kill this. Especially in soft water areas like the North West of England for example. Plus I know for a fact that virtually all garages whether they're main dealer or back street just use tap water.

[Ant]

"overkill" it's like £2 for a five litres of the stuff, even tesco stock it, hardly a hassle to get hold of

coolant is the blue stuff, bmw sell it unmixed, mix with de-ionised water 50/50 ratio

[MACK]

"overkill" it's like £2 for a five litres of the stuff, even tesco stock it, hardly a hassle to get hold of

coolant is the blue stuff, bmw sell it unmixed, mix with de-ionised water 50/50 ratio

Yep complete overkill. Totally pointless even BMW use tap water. Their spec listed above of 360ppm is twice the UK's very hard water at circa 180ppm. So why bother wasting even a little money? I certainly wouldn't wait to top up coolant or do a change till I got my hands on some.

[Crazy Harry]

365ppm in my location - I'm still for avoiding tap water.

Check yours here towards the bottom of the page: https://www.kinetico.co.uk/hard-and-sof ... t-water-uk

[GuidoK]

"overkill" it's like £2 for a five litres of the stuff,

If you compare it to the price of tap water, thats actually ridiculously expensive
About 1000 times more expensive or so.

btw I always buy the premixed stuff. But I use the cheapest long life g12+ available though.

[ronk]

365ppm in my location - I'm still for avoiding tap water.

Check yours here towards the bottom of the page: https://www.kinetico.co.uk/hard-and-sof ... t-water-uk

Useful link — I’m in a 37.5 area

[mcbeee]

Tap water is just fine. Distilled, deionized , reverse osmosis ... we had all that at work and we used tap water. The only thing we took pains over were the storage battery banks, they were a little more finicky.

You are mixing it with ethylene glycol and as long as it isn’t brown, lumpy and full of calcium it’s fine,

[Magicarcher]

Thanks for all the advice, never thought of tumble driers or de-humidifiers which sound like good idea, but I don't have one anyway.