Poodles;1275483 said:I've run the Royal Purple before...wasn't impressed.
Keep in mind that none of them will protect the cooling system as well as coolant. Corrosion protection, water pump lubrication, ect. They don't affect the boiling or freezing point as well (coolant raises the boiling point and lowers the freezing point).
Water wetter's effects aren't enough to replace the protection of coolant IMHO. If you're overheating, water wetter is a band-aid and won't save you in the long run...