Someone here (sorry forget who) said to use about 1 3/4 gallons (7qts) of coolant, roughly estimated that by heft of fluid left in the second gallon and filled the rest with distilled water, according to the hydrometer that gave dead on 50/50, if everything was completely accurate that would make 14qts total but neither my "heft check" nor the hydrometer are accurate enough to say it is not 15qts but that does say that 15qts is close enough
Just judging by the level change in the overflow I would estimate about a pint moves in/out of the bottle every heat/cool cycle, that should get the freeze point of the overflow down to safe in just a few cycles, concervitive guestimate 2 weeks (daily driven) to get the bottle to the exact same concentration as the rest of the system, law of diminishing returns, as they get closer in concentration the effect of the moving fluid does less to equalize the two
You should be fine before the real cold gets here
How cold does it get up there that you need 70% coolant?
Where I grew up in FL if it was green it is good as it rarely froze and when it did not very cold, shortly after I moved to GA we cot a cold snap (for us) it got down to 9*f, left for work at 11:00pm (night shift) in an old Cadillac with unknown service history and the heat never got warm, moving down the highway I smelled coolant, and then a few seconds later my overheat IDIOT LIGHT (no gage) came on, the radiator froze and split starving the engine (and the heater core) of coolant
Called my foreman and said I cannot come in because I overheated, he though I was lying, how can you overheat on the coldest night of the winter?
