When adding coolant to 1986 Honda Accord does water need to be mixed in with the antifreeze?

Answer 1

Yes a 50/50 mix of antifreeze and distilled water. I disagree, I'll explain why A 100% antifreeze solution is perfectly acceptable. However you will only get a small increase in protection against overheating or freezing as compared to a 50/50 mixture of anti-freeze and water. By the way, the water doesn't have to be distilled. If your water supply is hard or has some other mineral deposits then you should use soft water. In the near term, the iron content in hard water won't impede the overheating and freezing protection that you get from the antifreeze, but it will extend the life of your cooling system by preventing the iron ions (or calcium ions or whatever mineral is present in the water) from corroding and clogging the coolant passages. It will also allow for a more efficient heat transfer between the hot internal engine block surfaces and the antifreeze itself.