Added about a cup
I just had to add about 1 cup of coolant to bring my reservoir up to the MIN line when cold but I was told, by the guy at Auto Zone (I know, BIG MISTAKE!!), that the Prestone 50/50 mix was ok. It was yellow and it didn't change the color of what was in the reservoir so I'm wondering if I'm ok or if I should flush and refill at this point. I have a 2015 Ford Focus with the 2.0L DOHC. Yes, it's not the flashy fancy one and it's not a Mustang but it is a Ford!!!