I have seen many people list a wide variety of numbers on what the percentage of methanol is in the blue juice (washer fluid). I searched just about every company out there, and found out that regardless of the brand, the methanol percentage was consistent for whatever the temperature range was for the blue juice. It may have varied by 1-3%, but generally -20F was the same for all companies, just as all of the other temperatures were. I compiled a list of the different washer fluids by temperature, and then if you click any of them it will show you the MSDS (material safety data sheet) which will show you the methanol content.
I am not trying to say anyone is wrong, I am just trying to put out some consistent information, so I hope this is taken in the spirit it is given.