Difference between distilled and deionized water for auto use?

[malibu101]

After the recent coolant thread, and as often comes up, to use distilled water for coolant mix and batteries...
I have access to as much deionized water for whatever I need for my automotive use.

So, my simple question- Would it be good, bad, or indifferent to use DI water for coolant mix? Battery top off?
I just don't understand the differences other than the basic of steam distill versus however DI is made.
I probably wouldn't understand the chemist reasons and goooogle didn't really help with an answer.

I've always mixed my coolant with city tap water.
But I do use distilled for batteries.
Not about cost, just wondering.?

 

[PCustoms]

Who buys water to mix coolant?

(Sorry )

 

[Jeff Ivers]

De-ionization does not remove bacterial or organic contaminants. Could those contaminants react with antifreeze and cause a problem?

 

[Shiftless]

Who buys water to mix coolant?

(Sorry )

I suppose the people who do that are the folk who live where they have hard well water. Whether or not it makes a difference in the long run is debatable.

 

[Overboost44]

Who buys water to mix coolant?

(Sorry )

I buy water for my radiator, use it in my batteries and I even buy regular water to drink. Yes, I am on a well but I am not afraid to drink it.

 

[PCustoms]

I suppose the people who do that are the folk who live where they have hard well water. Whether or not it makes a difference in the long run is debatable.

I buy water for my radiator, use it in my batteries and I even buy regular water to drink. Yes, I am on a well but I am not afraid to drink it.

I see people didn't read the thread that the OP based this off of...

 

[Overboost44]

I see people didn't read the thread that the OP based this off of...

You are correct. I didn't search for the thread that this is based off of. You brought up paying for water to mix coolant.

 

[Leaflessshadetree]

Deionized is slightly better than distilled for batteries. I don't know if the difference would be noticeable.
Slightly worse than distilled for coolant because it is a little more reactive/corrosive can leach ions from metals especially with aluminum. Again I don't know that if the difference would be noticeable.
These days most (maybe all) of my batteries are sealed. No adding water.
I've used distilled, tap and well water for coolant (also premixed coolant) and haven't noticed a difference.

 

[njride]

honestly man i just use whatever's cheapest at walmart lol. never had issues with either one in my JK. deionized is like slightly purer i think but for a diff or coolant system it probably doesn't matter that much. if you're doing something with electronics or sensitive stuff maybe it's different but yeah id say save your money

What kind of diff do you put water in?

 

[msharley]

What kind of diff do you put water in?

Anything Chevy...

 

[finn]

Who buys water to mix coolant?

(Sorry )

Depends on where you live.

I wouldn’t think about it in My Mi house, but consider it mandatory in Tucson, the water is so bad.

What there is of it, anyway.

 

[Jack Ryan]

Distilled water is pure water - it contains no contaminants, no ions.

Deionised water is a cheaper alternative that can be used to top up batteries. It can contain contaminants but no ions.

Either is probably better than tap water in a radiator but coolant is best.

Jack

 

[Sumboodie]

We used distilled and deionized water for coolant. Blend several thousand gallons a week.

 

[johninct]

I suppose the people who do that are the folk who live where they have hard well water. Whether or not it makes a difference in the long run is debatable.

I

Who buys water to mix coolant?

(Sorry )

I buy Cat Brand and use it in everything.

 

[joe_padavano]

Who buys water to mix coolant?

(Sorry )

Truth. I realize that anecdotal "proof" isn't really proof, but I've been using tap water to mix with Prestone Green in my cars for over 50 years now with zero issues. And I can't remember the last time I had a battery that wasn't sealed.

 

[Meursault74]

distilled or DI water, I'd use whatever you could get the easiest/cheapest for car use.




Watch out for the windshield sprayer/washer too. If you don't want issues with the orifices clogging at the spray end. Yeah, I know some of you have been using hose water for 50 years without issue.
I recently bought some concentrated windshield cleaner for the reservoir and will dilute it with distilled water. Overall this is still cheaper than buying the ready to go cleaner.

 

[Hooked]

Although I understand the technical reasons, this is one of those things I just never worried about and use tap water for both. I'm sure there's possibly something bad happening in the engine block and the battery but I haven't seen any ill effects since I started driving and maintaining my own vehicles in 1962. I doubt that in the 3-4 years a battery lasts it's causing any noticeable damage and both my '94 f350 and 2002 Sequoia are doing just fine so there's that.
I suppose it's possible the failed oil cooler on my 1984 F350 6.9 diesel could have been a result of using tap water in the coolant.

 

[dcg9381]

I suppose the people who do that are the folk who live where they have hard well water. Whether or not it makes a difference in the long run is debatable.

It makes a difference. If you every had really high TDS water, you could see what it does in simple non-pressure not heated applications. If it will plug up my fixtures, it's definitely not going in my radiator. With reverse osmosis and a good water source, you can get TDS down to below 20. Not quite as good as distilled... But I won't put tap water into a battery or radiator unless it's an emergency.

City water varies in TDS (Total Dissolved solids).

 

[liliysdad]

Another tap water guy here…

 

[no704]

Used to run an envriomental testing UL approved lab. We made DI water on site. Got a new very expensive chamber and the tech was running the DI water in it for about a year. Fog generator rotted out. Only use distilled, especially in things with Al parts. It’s cheap insurance.

 

[Alinnh]

every shop I worked at the past 34 years used tap water. I think they would look at you like you were crazy for even suggesting to use anything else to mix antifreeze.

 

[Jack Ryan]

We used distilled and deionized water for coolant. Blend several thousand gallons a week.

What is the purpose of the blend?

Jack

 

[malibu101]

Thanks to all for your input.

I will probably continue to use the tap water from my house to mix coolant as it is more convenient than bring a gallon jug home from work.

However, the answer to my question seems to be that DI won't hurt anything.
THANKS for the advice!

 

[PCustoms]

However, the answer to my question seems to be that DI won't hurt anything.

Not sure how you got to that conclusion, but DI can (and will) erode many things including aluminum

 

[malibu101]

PCustoms- That's why I asked this question.

I saw leaflesshadetree said- "Slightly worse than distilled for coolant because it is a little more reactive/corrosive can leach ions from metals especially with aluminum. Again I don't know that if the difference would be noticeable."

That didn't sound as bad as you make sound.

 

[niget2002]

Not sure how you got to that conclusion, but DI can (and will) erode many things including aluminum

Straight di absolutely will. My assumption is he's pouring it in a radiator that still has fluid in it. As soon as it mixes, the water is no longer pure.

 

[bassJAM]

I used to use tap water back when I swapped vehicles every 2 years. Now I try to keep them 10+ years, so I use distilled. Its cheap and easy to find and more pure than deionized water.

 

[PCustoms]

Straight di absolutely will. My assumption is he's pouring it in a radiator that still has fluid in it. As soon as it mixes, the water is no longer pure.

I would risk it...

It is comical that across these two threads (my original "rant" and this) we've run the gamut from "any 'ole tap water" to D"DI is the best!" with a healthy dose of "who the hell buys pre-mixed antifreeze?" Thrown in

 

[zimman]

I'm trying to solve world hunger and peace. Ain't got no time for anything like bottled water. Tap it out. LMAO
Zim

 

[Paycheck]

Not sure how you got to that conclusion, but DI can (and will) erode many things including aluminum

Hadn’t heard that before. DI is big in the detailing community, never a mention of erosion issues. Where can I get more info on this?

 

[Sumboodie]

What is the purpose of the blend?

Jack

Removes everything from the water I guess? I'm not sure aside it's required by the manufacturer.

 

[rust in the eye]

What comes from various taps varies a LOT.
I have a private well that required around $5k in remediation equipment(20+ yrs ago) to make it drinkable. LOTS of dissolved minerals most are now mitigated but I won't put it in a battery* or cooling system. Distilled at wallyworld runs around a buck/gl. which I mix 50/50 with the coolant for all my cars.
Correct coolant chemistry has become important.
*"sealed" batteries can require filling too.

 

[cannuck]

I would like to hear from a chemist who works with antifreeze. As much as DI WILL corrode Al, not sure that is is any longer DI when mixed with AF. Easy worry to avoid - just use distilled or tap (IF you have decent domestic water supply).

 

[niget2002]

We use DI in our saltwater aquariums for top-off. When I had mine, I ran a 5-stage RO/DI filter to produce 55 gallons of water. The DI water is then used both for daily top-offs and to create make-up salt water for doing water changes. My aquarium was 120 gallons, so I did weekly 12 gallon water changes. Water top-off was roughly 10 gallons a week. I used the waste water from the RO/DI to top-off our swimming pool.

I still have the filter sitting in a box in the shop. It'd be interesting to make a few gallons and drop some aluminum in it to see what happens. I'd have to buy some new media, as what I have would be bad at this point.

 

[Jack Ryan]

Not sure how you got to that conclusion, but DI can (and will) erode many things including aluminum

Is that because it was not properly demineralised in the first place, or because it was contaminated afterward by, for example, absorbing CO2 and becoming acidic?

Of course distilled water also readily absorbs CO2 so both can have a pH as low as 5.5.

Thanks

Jack

 

[Dagny]

I remember dipping it out of the swamp with a hard hat one day when the thermostat stuck.

 

[Meursault74]

Is that because it was not properly demineralised in the first place, or because it was contaminated afterward by, for example, absorbing CO2 and becoming acidic?

Of course distilled water also readily absorbs CO2 so both can have a pH as low as 5.5.

Thanks

Jack

The water has no metallic ions in it and has a better ability to leach them out from the metal surroundings over time.

Water with metal minerals (ie tap water) won't leach as much for two reasons. The water already has a higher ionic strength. The minerals can also deposit themselves on the metal surfaces and build up over time. Protect and cause scale, which can eventually clog something.

For car cooling systems tap water or DI water alone, shouldn't be used. Mixing it with the "coolant" would remedy the issues for the most part.

 

[pima67]

Hey, an article in Popular Mechanics some 60 or maybe 70 years ago said use distilled water. So there!!!

 

[MileHighRover]

I'm pretty surprised by the amount of people that use tap water. Since I was a teenager everything I've seen and read, including every owner's manual I've referenced, has specifically stated not to use tap water in the cooling system, only distilled water. I've never once used tap water. I always have a gallon of distilled water on hand. I guess I'm too much of a rule follower.

 

[Jack Ryan]

The water has no metallic ions in it and has a better ability to leach them out from the metal surroundings over time.

Water with metal minerals (ie tap water) won't leach as much for two reasons. The water already has a higher ionic strength. The minerals can also deposit themselves on the metal surfaces and build up over time. Protect and cause scale, which can eventually clog something.

For car cooling systems tap water or DI water alone, shouldn't be used. Mixing it with the "coolant" would remedy the issues for the most part.

Thanks. I'm not a chemist so I won't go on but I am surprised that DI water and distilled water can corrode metal unless it contains dissolved oxygen, CO2 or other contaminants.

Hydration of aluminium oxide is one process, but that is very slow.

I guess I'll just have to remain surprised.

Jack