I investigated using the dextrol vs regular (glyceryn) based coolents. It seems the the dextrol was suposed to be better on a one to one comparison. The issues that complicated matters was if you needed to add coolant in an emergency or if coolant is mixed it causes problems. To me it seemed like the regular antifreeze was good if you used it before. Dextrol type may be better if you are starting from scratch. I have used water wetter with minor differences in the Texas heat. I tried it in my 1969 recently and noticed a slightly different needle position on the guage. To give an estimate, it would be about 5 at best. Lee 66 # 869 69 # 2055
