New OEM Antifreeze Mix %

Thought this might be of some general interest. I have a 2016 Ram CTD and I wanted to know with certainty the OEM water-antifreeze mix ratio before going to the northern Rockies in the dead of winter, where -50F shows up from time to time.

I got a simple refractometer from the internet. Checked it against pure distilled water to be sure that it showed pure water and it did. Then a sample was taken from the truck and checked, and it showed around 65% ethylene glycol, and protection down to the -65 to -70 F range.

I was never sure what the factory would put in, but in this case at least, I now know. This truck was sold with a block heater and in Idaho, so it would be set up for cold temps. But I suspect even a vehicle sold in FL would have the same mix.... though I have no proof of that.