well i dont have a temp guage on the YFZ but I used engine ice in my 310R and the YFZ,and my friend used it in his banshee and his dad used it in his Z400.........none of us had problems........and the fan equiped machines did not run the fan hardly at all compared to those running regular coolant ,,,,,but i have no concrete numbers to say yes or no
I am pretty sure that its only ENgine ICE that you cant add to anti-freeze. The ENgine ICE calls for you to drian and flush your cooling system with distilled water before you fill it with ENine ICE. I think the engine ice will start a chemical reaction with the anit-freeze.
I ran engine ice in my Z400 and it ran fine....i didn't know I was suspossed to flush the system with distilled water....I just drained the old stuff and added the new stuff with no problems.......The fan rarely came on so i'm guessing it worked alright