Sorry if this was discussed before, but if so I couldn't find it by searching.

I am familiar with Honda Antifreeze/Coolant Type 2 sold in a 1 gal jug at 50% concentration. Recently, I came across "Honda Genuine Antifreeze/Coolant Type-2 Concentrate for Extreme Cold Weather" sold in a 1 qt jug.

The intended use of this concentrate is to enhance low temperature protection from -34F to -62F. Assuming your coolant concentration is the standard 50%, you do this by draining 20% of your coolant capacity and replacing that amount with the Extreme Cold Weather Concentrate.

If the Extreme Cold Weather Concentrate is standard Type 2 coolant at 100% concentration, then following the above procedure would increase your coolant concentration from 50% to 60%. Coolant charts show that if you increase your coolant concentration from 50% to 60% you change your protection from -34F to -62F. Therefore, it seems to me that ""Honda Genuine Antifreeze Coolant Type-2 Concentrate for Extreme Cold Weather" is just 100% of the standard Honda Type-2 coolant. Am I missing something?

By the way, to me this is good news that we can obtain Type-2 in a 100% concentration.

 

Makes sense to me I guess. Never had to deal with it though since my area doesn't go below 0° F usually.

 

One reason I brought up the subject is in case someone wanted to do a coolant change like the one described in our DIY section by trustdestruction. His procedure uses distilled water to flush out the whole system. Since some water is left in the system, you can't obtain a 50% final mix if all you have to work with is the 50% Type 2. If the Concentrate for Extreme Cold Weather is 100% standard Type 2, then you can follow the above DIY.

 

That makes sense for sure. I usually never flush out my coolant system though. I just replace the fluids each spring with fresh 50/50 coolant.