What brand of anti-freeze coolant for -45 oC ?

I just bought my first Honda - NC750S. I will be riding it to Yellowknife, Northwest Territories, Canada (think Alaska). It will be stored in an unheated garage over the winter, where the temperatures fall to -45 oC.

Normal antifreeze/coolant is 50/50 mix of coolant and water. This mixture is rated only down to -37 oC. So I will need to use a 70/30 mixture, which is good for -64 oC.

I spoke to my Honda dealer; they only sell "Pro-Honda HP Coolant", which is pre-mixed at 50/50. Thus, this product won't work for me.

I would like to use "Prestone LongLife Concentrate", and mix it 70% with 30% demineralized water.
Antifreeze / Coolant | Prestone® Canada

Does anyone know if this Prestone product is acceptable for the Honda NC700/NC750 engines?

Much thanks ...

The key to compatibility with Honda motorcycles is that the antifreeze be "silicate free". Check the bottle of the Prestone Long Life for "contains no silicates" or something to that effect. I use the Prestone Long Life now that my Honda HP stock is used up.

What 670cc said

670cc said:

The key to compatibility with Honda motorcycles is that the antifreeze be "silicate free". Check the bottle of the Prestone Long Life for "contains no silicates" or something to that effect. I use the Prestone Long Life now that my Honda HP stock is used up.

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Thanks for this requirement.

...

Honda HP product meets ASTM-D3306 specifications,
Prestone Long Life meets the same specification. They are both silicate free.

Good, so Prestone's product will work for our Honda.

ASTM D3306 is a set of standards for light duty cooling systems (automotive). Here is some elaboration on what its requirements are, if you're interested:
ASTM D3306 - 11 - Standard Specification for Glycol Base Engine Coolant for Automobile and Light-Duty Service

Skeleton said:

Normal antifreeze/coolant is 50/50 mix of coolant and water. This mixture is rated only down to -37 oC. So I will need to use a 70/30 mixture, which is good for -64 oC.

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I'm in Kenora NW ONT and we see temps the same as Yellowknife. We get the cold arctic air flow from Hudson Bay and will see a couple of weeks in the -45C . Why are you changing the antifreeze? Are you scared that it's going to freeze? I don't think so. New cars in Canada have antifreeze mixed to -37C and they don't freeze. Ask an auto tech in Yellowknife if they change antifreeze on new cars to prevent freeze up. I've been an auto tech for 25 years and when we test in the fall if it's good to -37c it's good to go.

Ruggybuggy said:

I'm in Kenora NW ONT and we see temps the same as Yellowknife. We get the cold arctic air flow from Hudson Bay and will see a couple of weeks in the -45C . Why are you changing the antifreeze? Are you scared that it's going to freeze? I don't think so. New cars in Canada have antifreeze mixed to -37C and they don't freeze. Ask an auto tech in Yellowknife if they change antifreeze on new cars to prevent freeze up. I've been an auto tech for 25 years and when we test in the fall if it's good to -37c it's good to go.

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I had understood that antifreeze would 'freeze' solid when the temperature falls below -37 oC when mixed as a 50% ratio (standard mixture). For which, the water portion would result in 8% volumetric expansion. This cracks the engine.

Can you explain what happens to the 50%/50% antifreeze mixture when the temperature falls below -37 oC?

Skeleton

You have the right idea. Do what 670cc said, and find a coolant that meets both Hondas requirement and your temperature range requirement. No reason to risk it.

In fact, it sound like you've already found it.

Skeleton said:

I had understood that antifreeze would 'freeze' solid when the temperature falls below -37 oC when mixed as a 50% ratio (standard mixture). For which, the water portion would result in 8% volumetric expansion. This cracks the engine.

Can you explain what happens to the 50%/50% antifreeze mixture when the temperature falls below -37 oC?

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It doesn't freeze. If you want to bring the strength up drain some antifreeze out and add compatible antifreeze full strength and that will bring it up to the freeze protection. Like I said all new cars come with -37C protection and they don't freeze in Canada and if you don't believe that walk into a dealership in Yellowstone and ask if they're changing out the antifreeze. I've have antifreeze stored in my garage at 50/50 and it doesn't freeze. When it gets extremely cold, -50 it supposedly jells but I've never seen it. Never experienced -50. Coldest in my area is usually -40 to -45.

Agree it jells a little........I have seen this in RV anti freeze.........never freezes solid.....and car manufactures make one spec antifreeze for the whole North American market.