The Prius uses Toyota Super Long Life Coolant. It is rated by Toyota as good for 100k miles from the factory, then 50k miles each refresh from then on. It is premixed and pink (don't use the red Toyota Long Life coolant which has to be mixed 50%). JeffD
Actually I'm anti-coolant. I think an engine should be allowed to reach whatever operating tempature god intended!
Adiabatic engines - you can't get much cooler than that, or I suppose I should say hotter. I'm getting all caught up in the slang. Tom