Waterless or 50/50?

Picking a coolant for some can put you on that proverbial fence line and you’re just not sure which way to fall. You need your cooling fluid to prevent high pressure and air or vapor within the system. You need it to transfer heat away from the engine, but it also helps distribute temps more evenly too. Your choices for the most part are a waterless coolant or a mix like 50/50. The waterless coolant most often talked about is Evans NPG (NPG = non-aqueous propylene glycol) waterless coolant (Rotax recommended). Evans NPG is basically non toxic, non-corrosive and can operate at zero pressure. Its boiling point at zero pressure is 375F and the freeze point is -40F and was originally developed with the race car in mind.

Related Technical Article: 912/914 Cooling