Mixing OEM coolant with aftermarket

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2019 CX5 Touring/Preferred Pkg
My 2019 NA 2.5L has coolant below the Low marker. I haven’t had any issues yet (it’s still below freezing around here) but would there be any issue if I mixed the OEM stuff with something from Autozone? It’s the blue type coolant. Not sure if I should go to the dealer and have them top it off but then again the dealers around here will most likely make me wait 2-3 hours and charge for it too.
 
Do NOT mix other coolants with Mazda's FL22. Buy the right stuff, your car will be much happier and so will you.

Here's what I bought when I needed it. Not cheap but it's FL22 concentrate. If you buy this you'll need to add distilled water.


Here's the premix version and it's almost the same price as the concentrate. Both are 5 liters so why not buy the concentrate?


5 liters is WAY more than you need. You may be able to find FL22 in smaller amounts. Look around.
 
There is also a TSB out there for heater core being plugged by rust debris. That is a fairly expensive repairs when it happens depending on the models ( Cx-9 being the worst). To prevent this mazda added additional rust protector in their coolant. I am sure you can get something with similar rust protection somewhere, but doing the research and finding it might be tricky. Probably easier to just stick with the OEM stuff.
 
My 2019 NA 2.5L has coolant below the Low marker. I haven’t had any issues yet (it’s still below freezing around here) but would there be any issue if I mixed the OEM stuff with something from Autozone? It’s the blue type coolant. Not sure if I should go to the dealer and have them top it off but then again the dealers around here will most likely make me wait 2-3 hours and charge for it too.
If you did decide to use an aftermarket coolant, Peak Blue (if that's what you were looking at) is the wrong stuff. You'd want Peak Asian Green that has "Mazda: 1990 and Up" on the front label.


This stuff meets the basic Mazda requirements: ethylene glycol based, free of silicates and borates, rust inhibitors.

By all means use the Mazda FL22 if it is convenient to get your hands on it and certainly for a flush and fill to be on the safe side. But it would be a stretch to say adding a few ounces of the right Peak stuff to top off a 2 gallon system a couple of times between flushes is going to harm anything.
 
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I’d go with actual FL22. I topped up to the F line several years ago with Ravenol FL22 and bought that on Amazon. The price used to be MUCH better back then though. 1.5 L of Ravenol premix is like $28 now, and that’s about what Mazda charges for a gallon of OEM premix.

Call your dealer to see if they have any in stock. My local dealer didn’t so I had to order Mazda OEM coolant from an online supplier. MazdaSwag sells it for $20 per gallon premixed plus shipping, part number 0000-77-508F-20. They were fast and their communication is excellent.
 
Do NOT mix other coolants with Mazda's FL22. Buy the right stuff, your car will be much happier and so will you.


That's not true at all. Mazda Technical Service Bulletin No: 01-033/07 states
"FL22 coolant is compatible with current (Green) ethylene glycol coolant."

Ethylene glycol is the good old plain green stuff that's been around for decades.

The difference is, the old green is good for 5 years instead of 10.
 

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If you have to go in for the fuel pump recall, and it is a small amount you need, maybe ask the dealer if they could top it off for you at that time. I can't imagine them charging much to put in a few ounces of coolant, maybe they won't charge at all.
 
if you're only topping off the reservoir tank, stop overthinking it... just get distilled water and top it off... just a few ounces of water isn't going to dilute the coolant enough to really affect the freezing point... if anything, the coolant from the radiator will eventually mix with it and equalize, since the reservoir is connected to it, and when the engine is warmed up, coolant will expand into it

otherwise, putting in any aftermarket coolant will probably affect the coolant quality or life... it's not worth the risk, nor is it necessary to spend any significant amount of money (buying coolant) just to top off the reservoir... I've been using distilled water to just top it off every season for the past 5 years, and it's been fine
 
That's not true at all. Mazda Technical Service Bulletin No: 01-033/07 states
"FL22 coolant is compatible with current (Green) ethylene glycol coolant."

Ethylene glycol is the good old plain green stuff that's been around for decades.

The difference is, the old green is good for 5 years instead of 10.
I take this to mean that it's OK to add FL22 to old style ethylene glycol but not meaning to add old style to system filled with FL22.
 
"OK" in emergency, but you dramatically affect coolant life... you will need to change it after the coolant after it's 5 years instead of 10... you're better off putting in distilled water, so that it's not contaminated with inferior chemicals which affects coolant life
 
"OK" in emergency, but you dramatically affect coolant life... you will need to change it after the coolant after it's 5 years instead of 10... you're better off putting in distilled water, so that it's not contaminated with inferior chemicals which affects coolant life
Mazda says not to add water since it will decrease service life. So do with that what you will.

I would not assume that alternative products not designated FL22 are "inferior". For instance, Mazda's service interval after the initial 10/100,000 is 5/60,000. Aftermarket products such as the Peak product referenced above are consistent with that calling for a 5 year interval.

Why does Mazda slap FL22 on the radiator cap? Maybe because the Mazda brand draws more DIYers than most and they want to make sure owners don't goof with something incompatible. Why is Ravenol the only other brand with FL22 on the bottle? Perhaps they're the only ones willing to pay Mazda somethin' somethin' to use their proprietary designation.
 
I absolutely REFUSE to buy premixed coolant. Sorry, not paying $10+/gallon for literal water.

And because FL22 only comes premix (that I've seen), and because Mazda themselves specifically said that FL22 is completely compatible with good old fashioned green (which is $12/gallon for the concentrate when on sale), the answer is obvious for me.

Even though it's rated for 5 years instead of 10, the regular green is so much cheaper I'm still way ahead of the game.
 
. I absolutely REFUSE to buy premixed coolant. Sorry, not paying $10+/gallon for literal water.

And because FL22 only comes premix (that I've seen), and because Mazda themselves specifically said that FL22 is completely compatible with good old fashioned green (which is $12/gallon for the concentrate when on sale), the answer is obvious for me.

Even though it's rated for 5 years instead of 10, the regular green is so much cheaper I'm still way ahead of the game.
Yes, but does the 'good old green' contain silicates which can precipitate out and cause abrasion wear to water pump seals and form deposits. Something the 'newer' coolants avoid. I was really surprised with the cooling system cleanliness and improved hose life when acquiring a car that used the newer (at the time) coolant formulations. I do not miss the old green S#&t.
 
If you did decide to use an aftermarket coolant, Peak Blue (if that's what you were looking at) is the wrong stuff. You'd want Peak Asian Green that has "Mazda: 1990 and Up" on the front label.


This stuff meets the basic Mazda requirements: ethylene glycol based, free of silicates and borates, rust inhibitors.

By all means use the Mazda FL22 if it is convenient to get your hands on it and certainly for a flush and fill to be on the safe side. But it would be a stretch to say adding a few ounces of the right Peak stuff to top off a 2 gallon system a couple of times between flushes is going to harm anything.

I've already flushed (my mechanic machine evacuated old fluid and pumped in new) both cars (CX-5 and Mazda 6).

In that case I can go with Peak Asian blue or green. They are the same stuff except for the color dye. In my case I had the blue pumped in.

...The cool part is the Peak with Yellow capped (All Vehicles) bottle is compatible with either one. I noticed Peak played it safe and made their Peak Asian Blue/Green as well as the Yellow capped (All Vehicles) to be (an OAT coolant free of 2-EHA, silicate, nitrite, borate, and amines). So now I can top off as needed easily. Peak Yellow capped (All Vehicles) bottles can be found at Autozone, Target, WM, Harbor Freight, ect.
 
I take this to mean that it's OK to add FL22 to old style ethylene glycol but not meaning to add old style to system filled with FL22.
Right. The way it reads is that it's ok to mix new FL22 into regular green if necessary. That doesn't mean green will work well in a newer engine that requires FL22. The STB is from 2007.

All new syn oils are backward compatible with old dino oil. They mix ok and no ill effects. That doesn't mean it's ok to use dino oil in a newer car that requires synthetic oil. It won't ruin the engine immediately but engine life could be lower.
 
Mazda says not to add water since it will decrease service life. So do with that what you will.

I would not assume that alternative products not designated FL22 are "inferior". For instance, Mazda's service interval after the initial 10/100,000 is 5/60,000. Aftermarket products such as the Peak product referenced above are consistent with that calling for a 5 year interval.

Why does Mazda slap FL22 on the radiator cap? Maybe because the Mazda brand draws more DIYers than most and they want to make sure owners don't goof with something incompatible. Why is Ravenol the only other brand with FL22 on the bottle? Perhaps they're the only ones willing to pay Mazda somethin' somethin' to use their proprietary designation.
they say not to add water under the assumption of TAP WATER, which has lots of minerals/impurities that do affect coolant quality/life... distilled water has none of such... the coolant you buy at mazda is premixed with distilled water to begin with.... I really doubt adding 4 to 16 ounces of distilled water will drastically change the ethylene glycol/water ratio of a ~2.5 gallon cooling system to cause freeze/boiling point issues... the manual is really conservative and gives the most prudent advice-- rightfully so, for liability reasons... that simply means, with common sense and thought, you can ignore some things the manual says to do because from a technical standpoint, what I am advising isn't a big deal and won't be a problem... but if you want to be a mindless zombie and following the manual to the T, go right ahead... you won't hurt anything but your wallet, and your car will just be in tip top shape as those of us straying slightly into the gray area

the manual also says 5 years or 60k miles after the first change, because they're also assuming a drain and fill, which means about half the original coolant is still in the car/engine, which means mixing new with old will reduce its life... if you manage to get most of it out (without doing something stupid like tap water flushing), I can assure you that you can get 10 years or 100k miles out of it, just like before

motorcraft brand coolant also has FL22, under product number VC-10-A2, which is sold only concentrated and must be mixed with distilled water
 
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