It's very stable and anti-corrosive, but the specific heat is far too low. In other words it is a much poorer conductor of heat than a 50/50 water/ethylene glycol blend - lower even than pure ethylene glycol. For this reason I do not recommend it for most applications. In other words, your engine will run hotter. Your engine will actually run cooler with a 60/40 water/ethylene glycol blend as long as you don't experience boil over, but this mixture is more corrosive and provides less lubrication to your water pump. Instead, I recommend a 50/50 mixture with distilled water (deionized water is best but harder to find and $$$) and conventional coolant, not tap water, for best long term results in most engines, using the type of coolant recommended by the engine manufacturer for their engines. For diesels, follow your manufacturer's ratio and factory coolant recommendation exactly. Some, like Ford, are very specific.
Chip