I won't need to use a 2 to 1 solution. I might bee able to get by with a 1 to 1 solution. I already have wheel weights mounted that weigh about 70 lbs. each. I looked at a chart and it shows that for the size tires I have each tire filled with 25 gallons will result in an approx. 70% fill. Because of the wheel weights another 200 lbs. of weight need to be added according to the Yanmar manual. At 8 lbs. per gallon it looks like pure water will do. But where I live it does get into the low 20s and rarely into the teens. Not for long, but it does happen. So I am going to find out which will work better for lowering the freezing temperature to 15 degrees F, sugar or the safe anti-freeze. By better I mean weight, cost, and volume wise. This may mean freezing samples myself. With mixed sugar, anti freeze, and water. It could be fun.
Eric