coolant

the coolant would be the same that you put in a car no difference in the two.

yep same mixture. Water is the key to the coolant the antifreeze is only used to keep the water from freezing in cold weather and prevent rusting it doesn't help to cool the engine though. I prefer the premixed solutions that way theres no guessing. I've been driving mine in constant temperatures over 100 degrees for the past 2 months and haven't had any overheating problems so the additives like engine ice aren't needed. As long as you keep your radiator clean and routinely check the level you shouldn't have to change the fluid for several years or 30,000 miles or more.