Please help me understand cooling in Clarity.

[Landshark]

I was also thinking about this, and here are my thoughts.

Honda provided these instructions for a few reasons:

1. The HV system exists and needs instructions on how to replace the coolant.
   
   
2. Something happened to the HV coolant system, like the system started leaking or physical damage occurred to the coolant system.
   
   
3. The HV battery needs to be changed.
   
   
4. The car is very old or the mileage is high. (That's a good question: when does this condition happen?)

Furthermore, Honda's recommendation to test the coolant for proper concentration is based on prevailing weather conditions. For instance, a car operating in an Alaskan winter with very low temperatures would require coolant with a high concentration.

Less than 2 weeks ago you initiated this thread out of concern for changing the coolant at 100,000 miles. Now you seem to be trying to convince yourself that it isn’t necessary. “Oh, that information about how to change the coolant isn’t relevant to my situation”. At least that’s how is comes across, multiple reasons why you don’t need to do it.

Even the 50/50 coolant blend recommended for non-Alaskan environments can become weak and in need of some concentrate to restore its original strength. Testing it after 3 years and annually thereafter would be a wise practice. Our motorhome requires 10-11 gallons of coolant. It is relatively simple to replace, but somewhat costly due to the sheer volume. I test it annually and add concentrate as needed.

 

[Joe17]

Me personally, I would not change my EV coolant. Only the engine, and then only if it's needed not based on some abstract time in the manual. The manufacturers often are very conservative with their schedules.