This guy says pre-mix is a scam.

[zray1]

Problem with pre-mix is.....after you flush a system with water, some is left behind. Now how are you going to get the concentration up to 50/50? It will always be less.

Easy. Just get one of these refractomers which is calibrated for antifreeze concentration by percentage points. I have one. Very easy to determine the exact percentage of antifreeze in the coolant, has scales for both antifreeze types.

SMARTSMITH Antifreeze Refractometer Displaying in Fahrenheit for Checking Freezing Point of Automobile Antifreeze Systems and Battery Fluid Condition. Battery Acid, Glycol, Coolant, Antifreeze Tester

https://a.co/d/eujZbKI

 

[Capt W]

Unless you flush the engine with water.

after you flush a system with water, some is left behind

I flush all my engines with water, but always pull the block drain plug(s) and the heater core hoses. I finish the process with bursts of low-pressure air to blast out as much residual water as possible. My 50/50 refills (mixed myself with distilled) are always at published cooling system capacities.

Yes, it takes a while longer to do; however, for a job I accomplish every 5-10 years I think it's worthwhile to do it as completely as possible.

 

[FCD]

Here in Spain it's hard to find concentrate, almost everything is premix.

 

[Escape08]

Most likely car manufacturers use pre-mix coolants rather than buying concentrate and mixing it with water

 

[Snagglefoot]

if you flush with water and use premix anywhere where temps get really cold like Minnesota, Montana, North Dakota, Alaska and a lot of Canada, you are asking for problems. There is no way to get to 50/50 if there is water in the block before you pour pre-mix in the radiator and coolant jug. When I flush with water, I pour straight 100% coolant into the rad and when I check it a few days later it usually comes out to either 50 or 60 % coolant.

A lot of shops don’t flush. They just drain the rad and fill with premix. Only half the fluid is new. If that works for you just do it.

 

[ArcherDriver]

Well, if you use an antique tester, your results may vary.

The guy who says premix is a scam is full of it. I've been using premix toyota for 322,000 miles for 15 years and same water pump. Always some expert on the internet to tell you you're doing it wrong. Here's the real sacrilege: I don't flush, either.

 

[bunnspecial]

Deionized water is not as pure as distilled water. The deionization process only removes ions, it does not remove organic matter such as viruses and bacteria that may be present in the source water.

Distillation removes both ions AND organic matter.

Either method can give you water about as pure as you want.

In a past job, one of my duties was day to day maintenance on a “house” DI system. Our system guaranteed 1 megaohm/cm, and considering that this supplied a dozen chemistry research labs, they’d know if the water wasn’t good.

Our system had activated carbon in one of the resin tanks as an organic scrubber. We also had a separate particulate filter unit combined with a sterilizing UV light. The system ran 24/7 other than maintenance shut offs(normally resin and filter changes) and water continuously recirculated throughout.

Some labs in our department had ultra pure systems(18 megaohm) that started with the house DI and ran through additional ion exchanges and carbon filters. They finished up with a .2 micron filter in the dispenser. Those systems, with proper maintenance by certified techs, would have been fully suitable for any medical use and in fact you will find them in medical(and microbiology) labs everywhere. They are in effect really fancy deionizing systems.

Distillation has its own issues with contamination. The condenser surfaces are a prime breeding ground for bacteria, so without care distilled water can quickly turn nasty. Any water can grow nasties if stored, and deionizing tends to be more suitable for generating on demand rather than in batches.

 

[350Rocket]

its always better to buy concentrate and distilled water. that way you know its 50/50.

I've always done it that way but I'd been recently (when I changed my water pump on my Silverado) wondering if there would be any advantage to the premix, over mixing it myself. I guess that's a no.

 

[350Rocket]

Here’s my take as someone that sells a lot of coolants. Over 1m gallons a year.

If you consider yourself an average person, which I consider myself an average person. 50% of people are dumber than you.

So while you may be able to mix 50:50 coolant reliably and use decent water. Someone out there is going to think since it’s yellow/gold/orange, they should mix it with the respective color Gatorade, in a 1:20 ratio.

At the end of the day, coolant blenders make 50/50 for ease of use. Both because some end users don’t want to screw around. And, some are bluntly too inept to figure out how to mix something.

I was changing the thermostat on my sister in laws boyfriends car and asked him to grab some antifreeze on the way to my place, specifically told him to get the concentrate and the deionized water (that's what they carry at Canadian Tire) but he showed up with premix. Oh well, made it easier for me and not my $.

 

[Jarpin]

Deionized water is not as pure as distilled water. The deionization process only removes ions, it does not remove organic matter such as viruses and bacteria that may be present in the source water.

...Because you can never be sure if the engine could get infected with viruses and bacteria....

 

[mrbreezeet1]

Another one for DIY. Assuming available, buy concentrate and mix rather than pre-mix. You are paying extra for the convenience factor and may not be able to trust the mixologist! Why pay extra if your drink is diluted?

I know right? How hard is it to add half water to half antifreeze.
They must think people were stupid or something.
"Oh yeah this is easier I'll just get this"
Never mind that you're paying one and a half times or thereabouts, if you were to mix it yourself.
SMH

 

[Number_35]

I use the manufacturer-specific premixed OEM coolant from Canadian Tire for the Grand Caravan and the Kia Sedona.

All prices are in C$.

4 l pre-mixed coolant = $21.99 + $0.75 eco fee + 12% sales tax

Total cost = $25.47

**********

4 l concentrate = $32.99 + $0.75 eco fee + 12% sales tax

4 l distilled water = $2.99 + $0.03 eco fee + 12% sales tax

Total cost = $41.17

But, there's enough concentrate and distilled water for two drain-and-fills, so the cost per drain-and-fill would be just $20.59

**********

So by using concentrate I would save $5 per drain-and-fill.

The hassle of mixing separate products, and storing the leftovers, is not worth it to me - I'll stick with the pre-mix.

**********

I use pre-mixed FL-22 from the dealer for the Mazda5. Last time I bought some, it was actually a bit cheaper than the OEM coolant. It's not available as concentrate.

 

[350Rocket]

I use the manufacturer-specific premixed OEM coolant from Canadian Tire for the Grand Caravan and the Kia Sedona.

All prices are in C$.

4 l pre-mixed coolant = $21.99 + $0.75 eco fee + 12% sales tax

Total cost = $25.47

**********

4 l concentrate = $32.99 + $0.75 eco fee + 12% sales tax

4 l distilled water = $2.99 + $0.03 eco fee + 12% sales tax

Total cost = $41.17

But, there's enough concentrate and distilled water for two drain-and-fills, so the cost per drain-and-fill would be just $20.59

**********

So by using concentrate I would save $5 per drain-and-fill.

The hassle of mixing separate products, and storing the leftovers, is not worth it to me - I'll stick with the pre-mix.

**********

I use pre-mixed FL-22 from the dealer for the Mazda5. Last time I bought some, it was actually a bit cheaper than the OEM coolant. It's not available as concentrate.

So you're paying $10 more for the convenience. My personal logic is that when I pay less and mix myself I get extra jugs to store the old stuff, plus I buy a little extra water and use that to a bit of a "flush" before refilling with extra concentrate to make up for the water still in there.
Yes it might not be as convenient but I get a more thorough exchange of coolant and pay less.

 

[tcp71]

Either method can give you water about as pure as you want.

In a past job, one of my duties was day to day maintenance on a “house” DI system. Our system guaranteed 1 megaohm/cm, and considering that this supplied a dozen chemistry research labs, they’d know if the water wasn’t good.

Our system had activated carbon in one of the resin tanks as an organic scrubber. We also had a separate particulate filter unit combined with a sterilizing UV light. The system ran 24/7 other than maintenance shut offs(normally resin and filter changes) and water continuously recirculated throughout.

Some labs in our department had ultra pure systems(18 megaohm) that started with the house DI and ran through additional ion exchanges and carbon filters. They finished up with a .2 micron filter in the dispenser. Those systems, with proper maintenance by certified techs, would have been fully suitable for any medical use and in fact you will find them in medical(and microbiology) labs everywhere. They are in effect really fancy deionizing systems.

Distillation has its own issues with contamination. The condenser surfaces are a prime breeding ground for bacteria, so without care distilled water can quickly turn nasty. Any water can grow nasties if stored, and deionizing tends to be more suitable for generating on demand rather than in batches.

How does DI remove calcium and other hard water particles? Distillation obviously does, but are those filtered out at 0.2 microns?

 

[Number_35]

So you're paying $10 more for the convenience. My personal logic is that when I pay less and mix myself I get extra jugs to store the old stuff, plus I buy a little extra water and use that to a bit of a "flush" before refilling with extra concentrate to make up for the water still in there.
Yes it might not be as convenient but I get a more thorough exchange of coolant and pay less.

$5/vehicle/annual drain-and-fill/vehicle x 2 vehicles, or possibly 3.

You're right, that's actually probably worth it to me. It's not a lot of money, but there's no point in wasting money either.

I could switch the Mazda over from the premixed FL-22 from the dealer to the OEM concentrated coolant for Mazdas.

For three vehicles, that's $15 of after-tax savings.

 

[Malo83]

All I do is flush the system, add a jug of Prestone with water and your good to go, never had any problems in my last 55 yrs of driving.

 

[bunnspecial]

How does DI remove calcium and other hard water particles? Distillation obviously does, but are those filtered out at 0.2 microns?

Ion exchange. That's the whole principle of how DI works.

 

[brianl703]

...Because you can never be sure if the engine could get infected with viruses and bacteria....

I'd be more worried about bacteria degrading the ethylene glycol coolant as it sits on the shelf waiting to be used.

 

[paulo57509]

I know right? How hard is it to add half water to half antifreeze.
They must think people were stupid or something.
"Oh yeah this is easier I'll just get this"
Never mind that you're paying one and a half times or thereabouts, if you were to mix it yourself.
SMH

This reminds me when McDonald's introduced the quarter-pounder. Then Burger King brought out the one-third Whopper. No one bought it because 1/3 is less than 1/4.

 

[Oillover]

The hassle of mixing separate products and storing the leftovers is not worth it to me - I'll stick with the pre-mix.

+1