Change distilled water coolant?

[thstone]

I use distilled water + water wetter in my Spec Boxster.

I change it every 2-3 years to replenish the additives in the water wetter because the water wetter gets slowly diluted over time as I top up using only distilled water.

Water alone is a better conductor of heat (+17% heat capacity at 220F as compared to 50/50 antifreeze). Plus, in the case of a leak/incident, water + water wetter doesn't create an oily slick on the track like antifreeze.