Classic/Antique Car Repair: 69 Camaro Coolant, 69 camaro, plain water


Question
Hey, Just a quick question, any idea how big a radiator is so i can make my 50/50 mixture easily? Oh and if i only use my car for half a year and when i do its not a lot, is there a big difference if i use tap water compared to distilled? Thanks

Answer
I don't think you need a 50/50 mixture.  The antifreeze companies tell you that because they want to sell more product, but a 30% mixture is plenty, unless you live at the north pole in winter!  You should run the same mixture year round, because you need the anti-corrosion additives in the system even if you are not worried about freezing.

Your car has about 20 quarts coolant capacity, so if you put in 7 quarts of anti-freeze, then top it up with plain water, you are good for 2 years.   As for what water, if you have really hard water where you live, I guess distilled is better, but I use tap water all the time, and I've never seen a problem because of it.

Dick.