It's that time of year and I was wanting opinions on antifreezes that claim to mix with any make, model or color of coolant. Both my vehicles require Dex Cool which some don't like. I also read about some being concerned about coolant PH levels but when you ask auto parts stores about getting some PH strips, no one has any. The reason I mentioned PH is because I was wondering if I could get by with a radiator drain and refill instead of a flush. My coolant temperature and boil points still check OK and are clean but they've been in my vehicles a while. I have a S10 4.3L and a HHR 2.2L. What do some of you use if you don't use Dex Cool and do any of you check your coolant PH?