Coolant

[radioguy41]

50/50 is the sweet spot. 90/10 would beg the question "Why bother?". If AF content goes beyond 50% the coolants ability to cool goes down which can cause overheating. More water = better cooling, more AF = better freezing protection. The optimum balance point is a 50/50 mix.

You get some rust prevention abilities and lubricity. But the sweet spot on those little yanmars is 25/75 with the latter being water

In Carolina maybe, not in PA or north, something would crack or split come Winter.

[Clemsonfor]

50/50 is the sweet spot. 90/10 would beg the question "Why bother?". If AF content goes beyond 50% the coolants ability to cool goes down which can cause overheating. More water = better cooling, more AF = better freezing protection. The optimum balance point is a 50/50 mix.

You get some rust prevention abilities and lubricity. But the sweet spot on those little yanmars is 25/75 with the latter being water

In Carolina maybe, not in PA or north, something would crack or split come Winter.

You guys are missing the point, this is for OVERHEATING. Clearly if you have severe cold winters you would need to strengthen the mix for colder protection. Overheating is not a problem if your lows are 15f and day highs in the 30s. The over heating would obviously be in the summer which is where my question comes about. I have not read about it here and no one talks about a low antifreeze ratio so it must not be a problem. But these tractors were designed for use in Ag fields and all day use. Like I said I am also into the vintage yanmars and it is a big problems in the hot summers where your really working the tractors, that is with the thermosyphon models. But they don't hold much coolant. I think mine holds a gallon and a half and it's a size or two larger than the thermosyphon models. They have the same radiator and I believe the blocks are similar sizes so I would think capacity would be about the same. But anyway I believe the answer to the question has been given , that these tractors are not picky when it comes to the antifreeze ratio in the summer heat.