|
Hi Jim - Antifreeze does two things - protects from freezing, and protects from corrosion. It may also act as a water pump lubricant, but I'm not convinced on this one. The mix ratio determines the degree of protection from freeze-up. 50-50 covers you to about 35-40 below F. If you don't get that cold, you can use less than 50% antifreeze - containers usually have a chart of ratios for various temperature protection on them. Antifreeze also protects engines from corrosion. Rust on the older cast iron engines, and electrolytic action (read battery acid behaviour!) on the newer multi-metal engines. These corrosion protection additives for the newer engines wear out - which is why the mfrs recommend regular replacement, to keep the engines from self-digesting. We haven't found this to be a problem with the older engines - the antifreeze itself seems to keep the rust down. There is some advantage to distilled water. Some of the chemicals in ordinary water settle out on the first heating (like teakettle scale). This, and dirty water, can build up deposits in the bottom of the block and rad, and on the rad core. We reuse our antifreeze, topping up with raw to bring it up to (or down to?) strength, to reduce the amount of fresh water (and fresh guck) added.
Also eliminates an environmental problem in disposal of the used product. Long winded - hope it helps.
| 
