I'm using Engine Ice myself.
Besides being non-toxic (propylene glycol based), it also doesn't become acidic over time as the ethylene glycol based coolant does.
It also doesn't have additives that can damage water pump seals.
Engine Ice comes pre-mixed 50/50 with deionized water in 1/2 gallon containers.
Now if your racing, then some tracks only allow water, but some may also allow Water Wetter. It's a coolant, but not an anti-freeze as Engine Ice is.
Regardless of which choice, the ideal water to use is deionized water, followed by distilled water. Use tap water only if you have no recourse.
Deionized water is chemically pure water with absolutely no trace minerals.
Distilled water still has some trace minerals and tap water can have tons of dissolved minerals that can wreck havoc with your cooling system.
i ended up going to the dealer and buying the premixed oem honda stuff. i chaged it about an hour ago but i just saw your post now. thanks though.
i have reverse osmosis water at my house and i think that would have been ok. i decided on the honda stuff though because my mechanic made me paranoid. he explained to me that he has an rc51 at his home garage right now with major rad problems. so, i bought honda coolant and peace of mind.
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